Phosphogypsum is a by-product in the wet process for the manufacture of phosphoric acid (ammonium phosphate fertilizer) by the action of sulphuric acid on the rock phosphate. The disposal of phosphogypsum is a serious environmental problem. This problem along with the scarcity of cement, environmental pollution associated with the manufacture of cement and its increased cost can be solved to some extent by replacing a certain quantity of cement in concrete with phosphogypsum. Our present study deals with the experimental investigation on compressive strength, splitting tensile strength and flexural strength of phosphogypsum concrete. The study aims to determine the optimum amount of phosphogypsum that can give maximum strength to concrete. The experiment consists of testing partially replaced phosphogypsum concrete using 0%, 2%, 4%, 6%, 8% and 10% replacement of cement with phosphogypsum. Based on the experimental investigation conducted and the subsequent analysis of test results, the following conclusions are drawn. The percentage increase in compressive strength (at water-cement ratio 0.5) at 8% phosphogypsum content, when compared with plain concrete is more than 20%. The percentage increase in split tensile strength (at water-cement ratio 0.5) at 8% phosphogypsum content, when compared with plain concrete, is around 10%. The percentage increase in flexure strength (at water-cement ratio 0.5) at 8% phosphogypsum content, when compared with plain concrete is around 30%.