The Common Admission Test (CAT) is an all-India test conducted by the Indian Institutes of Management (IIMs) as an entrance exam for the management programmes of its seven business schools. About 250,000 students took CAT in 2008 for about 1500 seats in the IIMs. This is said to make the IIMs more selective than the Ivy League Universities

The test is multiple-choice based with roughly one-fourth negative-mark penalties for wrong answers, and traditionally comprises three sections that span the domains of arithmetical problem solving, geometry, statistics, data interpretation, logical reasoning, puzzles, and English language skills. It is held on the third Sunday of November each year. The test duration was two hours prior to year 2006, but since 2006, it has been extended to two and a half hours. The total number of questions has varied from 180 (prior to year 2000) to 150 (from 2001 to 2003) and has gradually decreased to 75 (in 2006 and 2007). However, in 2009 the number of questions increased once again and became 90 (40 in Verbal Ability and 25 each in Quantitative Aptitude and Logical Reasoning and Data Interpretation). This trend has seen the CAT evolve from a speed-based test to an exam that evaluates fundamental abilities of candidates in the aforementioned areas.

The CAT is the first step for admission to the IIMs. After the test, by the second week of January next year, the IIMs declare exam scores and put up a list of candidates who are eligible for the next stage of a group discussion and an individual interview. The scores are relative and are calculated on a percentile basis for individual sections as well as for the total. Candidates invited for the next stage usually possess total scores that are in excess of 99 percentile and, more importantly, also possess balanced high scores across all the individual sections.

On 1 May 2009, it was announced that from CAT 2009 would be a Computer Based Test.

From 2009 CAT has changed From "paper based" to "Computer based test"-CBT, much more like GMAT. The first phase of CAT 2009 was over a 10 day test window from 28 November 2009.The test was conducted by Prometric.The test came under a lot of controversy over virus attacks leading to server crashes from the first day, inconvenience to candidates, software glitches and rampant cheating. See Prometric#Controversies.

The second phase of CAT 2009 will be on January 30th and 31st, 2010.The following candidates would be allowed to sit for the test in the second phase of CAT 2009

Those who could not take the test due to planned or unplanned closure of their test lab and were not rescheduled later in the first phase.

Those who were rescheduled but could not appear for the test because of notice period of less than 48 hours.

Those who were rescheduled but could not appear for the test as they were rescheduled in a city different from their original choice.

Those who pressed the End/Quit button within the first 120 minutes during the first three days of the testing window and have not been rescheduled yet. (If a candidate in this category chooses not to take the rescheduled test, then his/her score from the first phase of testing will be retained.)

Those who completed the test in more than 140 minutes of clock-time* due to computer disruptions. (If a candidate in this category does not appear for the rescheduled test, then his/her score from the first phase of testing will be considered null and void.)

Those who completed the test in 136 minutes to 140 minutes of clock-time* due to computer disruptions would have an option to take the rescheduled test. (If a candidate in this category does not appear for the rescheduled test, then his/her score from the first phase of testing will be retained.)

Those who experienced difficulties due to various kinds of disruptions such as frozen computer screen, blank screen, and data/graphic elements not displaying properly; identified through site reports recorded at the test labs and have not been rescheduled yet.

Clock-time refers to actual elapsed time from the start of the test to the end of the test for a candidate. This is different from the time indicated by the count-down timer which was displayed on the computer screen.

Now there are talks that the CAT should be made flexible like the GMAT or GRE with multiple attempts in a year, dates of choice and bankable scores .