Calyampudi Radhakrishnan Rao was born in Hadagali, Karnatka state, India on September 10, 1920. He received an M.S. in mathematics from Andhra University in 1940 and then an M.S. in statistics from Calcutta University in 1943. In 1944, Rao joined the Indian Statistical Institute as a statistician. While there, he worked under Mahalanobis, who sent Rao to the anthropological museum in Cambridge to analyze the data collected by a British expedition. Through this, Rao became employed at the Cambridge museum for a few years, at the same time he was working through a Ph.D. degree at King's College under R.A. fisher, where he helped Fisher's study on the genes of mice. He received the doctorate in 1948. He also later received a ScD from Cambridge in 1965 because of his published works in statistics.

Rao contributed to the filed of statistics in many ways. One of them occurred while he was working for his Ph.D. under Fisher. He was working on the anthropological museum at the same time, and while working on that project he developed a test to use for the classification of many categories, like Fisher's discriminant function for the classification of two categories. Rao's question was 'given a set of measurements, is there further information in an additional set of measurements?' This is the test that he developed and that he used in his thesis. Fisher loved the test, because it was an extension of a test he developed in discriminant analysis.

Another famous result of Rao's is the Cramer-Rao inequality. This came about as an answer to a student's question. Rao had proved Fisher's inequality that the asymptotic variance is not smaller than one divided by the information. A student then asked Rao to prove it for finite samples. Rao worked all night on the problem and came to class the next day with the inequality , using unbiasedness and the Schwarz inequality. This was in January of 1944. It led to Rao looking at sufficient statistics, which led to the Rao-Blackwell theorem. This theorem was completed in 1945, two years before Blackwell's work in 1947.

Rao did a lot of work in many different areas in statistics. Some of those areas include multivariate analysis, estimation, second-order efficiency, differential geometry, and orthogonal arrays. His work on orthogonal arrays led to important inequalities in coding theory. He also created the Langrangian Multiplier Test which is used in econometrics literature.

The two most influential people in Rao's life were P.C. Mahalanobis and R.A. Fisher. Both caused Rao to think in a new way and to create his own problems to solve. Both stressed more theoretical and methodological thinking instead of just simply trying to solve problems mathematically.

Rao has many interests outside of statistics. He truly enjoys gardening and actually used plants for statistical experiments. He once tried to come up with a way to have flowers all grow so that they unfolded in a left-handed manner, because those types of plants are more productive. However, they were not able to come up with a solution, because some of the data may have been in error from tampering with the plants.

Rao also has an interest in photography, although that is a past-time he is only able to pursue in the United States because of availability of photographic equipment in India. He also enjoys cooking, dancing, and music.

Rao has received many awards, including the Shanti Swarup Bhatnagar award of the Council of Scientific and Industrial Research, and the Mahalanobis Birth Centenary Gold Medal of the Indian Science Congress. He has also received nineteen honorary doctorate degrees from Universities around the world.

Rao has over 300 research articles and thirteen books to his credit. One of his books, Linear Statistical Inference, has already been translated in six major languages and is the most cited book in statistics in econometric work.

Rao has had a very successful career and is by no
means slowing down. In the next few years he may be going to
third world countries to help them start statistical programs
of their own so that they will not be dependent on other countries.
He has absolutely no plans of slowing down.