This study was conducted to determine the effects of molasses as supplement on mycelial colony growth and basidiocarp production of Pleurotus sajor-caju (Fr.). Five treatments with composted substrate combination of rice straw, sawdust, urea, and lime and supplemented with different concentrations of brown sugar and molasses were evaluated. Based on the results of the study, brown sugar and molasses used as supplements in the growth substrates of Pleurotus sajor-caju significantly enhanced the growth of mycelial colony when applied at the right concentration. Likewise, composted substrate supplemented with fifty percent of both brown sugar and molasses supported the heaviest basidiocarp production among all treatments. Two species of Mycodrosophila and unidentified small, shiny beetles were observed alighting on the bagged substrates and basidiocarps of Pleurotus sajorcaju. White insect larvae infested the base and cap of the basidiocarps. A cottony white fungus was observed contaminating the plated substrates except for the untreated bags. Contamination was not observed on the bagged substrates. Based on the cost and return analysis, the composted substrate with brown sugar and molasses supplements produced a average total yield of 873 grams and net income of Php 93.75 in five fruiting bags only.