A study was done to compare the production efficiency, in terms of total wet and dry larval yield and average weight of larvae of Musca domestica, reared at a constant temperature and nutrient supply but with increased larval density per unit of feed supplied. Wet weight yield increased with increased stocking density at a rate of 16.74 g/0.1 g eggs added while dry weight yields increased at a rate of 2.75 g/0.1 g eggs added. At the maximum rate tested, (6.318 eggs/g wet feed) no decrease in rate was observed and it is therefore concluded that the maximum wet and dry yields will be obtained at rates even higher than 6.318 eggs/g wet feed. Average larval weight was significantly influenced by density with the maximum observed at 3.159 eggs/g wet feed with a constant decrease up to 5.002 eggs/g wet feed and no significant differences observed at higher densities. It was thus concluded that, for the purpose of mass rearing larvae of M. domestica for biomass conversion, larval density as expressed per unit of nutrient supplied could be increased to levels of above 6.318 eggs/g wet feed but, for the production of breeding stock densities, should be maintained at levels of 5.002 eggs/g wet feed or lower.