This study employs Analysis of Variance in a multi-factor study of the determinants of compressive strength of concrete. Previous studies have employed single factor designs. The specific purposes of the study are (1) to identify the main factors and (2) to study the interaction effects of the various factors using a three-factor Factorial Experiment. It is observed that the results obtained using Analysis of Variance do support the observations of other researchers, i.e. the main controlling factors are water/cement ration, aggregate/cement ration, age, and method of curing.