Shortest time tp PhD? - What is the shortest time to finish PhD? (Mar/15/2008 )
From your experience, what is the shortest time to finish PhD that you have heard of-In the US?
And what field was it in and what University?
thanks in advance
In the States, usually it will take about 5 to 6 years. I know in the States, the PhD is the longest if you compared to the EU countries or Australia for instance.
I am interested too if anyone can tell me the answer in the States.
I've heard of a 3 year PhD. But even the director of the program (when he told me) said - 'I don't know what was going on with him'. So it must have been some controversery 
I've heard that in the states, the students begin PhD immediately after graduation. So the PhD lasts longer (5-6 years).
In Canada, we do a Master Degree first (2 years) and then get to PhD for 3-4 years. So if you already have a Master, the lenght of your PhD maybe shorter.
Try Germany, I finished my PhD in 3.5 years (including an year in Master's).
really? 2.5 years for PhD? that is really short! Is it really possible? How I wish i am as capable as you are!
Really often, the lenght of the PhD do not go with the capabilities of the person, but with the technical difficulty of the projet. Some projects, for whatever reasons, won't work.. It that case, you can't go faster.
But some projet can go with the person's capability. Hope this applies to you, Timjim 
It very much depends on:
- The field
- The university
- The advisor
- The maturity of the student
- LUCK
Business
A PhD in business could be very quick as most of the data one needs to gather already exists and can simply be downloaded...One does not run experiments, worry about experimental errors, have lab chores, etc... A PhD in business can easily be done in three years.
Biology
A PhD in Biology, from some universities, CAN be done in 3 years, but it wouldn't be easy... You'd be working constantly...
I know one young man who finished a PhD in Bio-engineering in 3.5 years but he was exceptional, and, in my opinion, had a relatively easy project. One thing that REALLY helped him was that his research was a continuation of research he had done as an undergraduate student...
TYPICALLY, in the U.S. to get a PhD:
- you have a required number of courses
- You have to pass a qualifying exam or exams of some sort
- you have to find/discover/develop something new and write a disertation on it.
The first two years are ussually focused mostly on Coursework... Many students make the mistake of not taking their research seriously in the first two years.
THE ADVISOR - THE ADVISOR - THE ADVISOR - THE ADVISOR - THE ADVISOR -
The advisor makes a HUGE difference... You could have a supportive advisor or one that ignores you... You could have one with funding or one that runs out... You could have an Advisor that wants you to graduate and have a career or you could have an advisor that wants to keep you working as a slave for many years....
Choosing the right advisor may very well be the most important decision a new graduate student makes... It's something they should consider before they accept the university they attend...
I finished my Ph.D. in Virology in 4 years. I think it was exhausting. I heard from other people they did it in about 3 years. It strongly depends on the topic and what you want to achieve. 
Best
AdoMad
I am interested too if anyone can tell me the answer in the States.
I am a graduate student in Denver, Colorado and work in a lab with post-docs who got their degrees in Europe. We've figured out that it's all pretty much the same but things are just called different names and set up differently.
In the United States, your Phd work will take 5-6 years but your first two years, you are simply a graduate student. At the end of your second year (or beginning third) you must pass qualifying exams. These are different at each university and program. Mine was to write a major and minor thesis proposal (in NIH grant form) and then go through a four-hour oral exam with my committee (5 professors). Once you pass this, you become a "PhD candidate" but are eligible to get the Masters, if you wish to leave the program. Otherwise you continue working in the lab for another 3-4 years until your committee feels you have done enough work on the thesis and give you permission to write the dissertation.
There are other programs available which are only designed to get a Masters but if you change your mind after earning the Masters and go back for a PhD, you may wind up taking longer overall since the university will want you to go through the coursework to fufill their specific requirements (usually regardless to the work you did earning the Masters). You are much better off if there is any way to just continue the work you did for the Masters rather than choosing a whole new field.
Personally, the fastest I've seen someone graduate is at the end of the fourth year (two years of thesis lab work after qualifying). This is an extreme that really surprized a number of people. Generally it's considered graduating early if you can defend your thesis sometime before completing your fifth year. I just started my fifth year and there is a small handful of students in my year writing. They generally are the strongest students in the program and a couple who just happened to have really good projects/advisors/luck.