The size of the adipocytes, the main cells of the adipose tissue, has been the objective of several studies because of its relationship with the development and metabolic activity of this tissue. The bimodality of their distribution into the tissue makes the analysis sometimes difficult. Thus, a method based, on testing the unimodal distribution vs. bimodality is presented. Some descriptive parameters appropriate for the bimodal distribution are also shown. A simple software has been developed for its application, being used to analyse data from two previously published studies about adipocyte development. Results show the interest in the use of the test of bimodality rather than the simple visual inspection of distribution histograms. Furthermore, when unimodality is rejected, the use of descriptive parameters of bimodality, as the percentage of adipocytes above the inflection point between the two peaks, allows a better comparison among experimental treatments.