An experiment was carried out in the laboratory of the Mushroom Development Institute, Savar, Dhaka from July to December 2019 to determine the effect of the sawdust composting period on the yield and yield attributes of different oyster mushroom varieties. The experiment was laid out by following Completely Randomized Design (CRD) with three replications. Three varieties viz. V1 (Pleurotus djamor), V2 (Pleurotus ostreatus) and V3 (Pleurotus florida) with six different days of composted sawdust such as T0 (0 days), T1 (5 days), T2 (10 days), T3 (15 days), T4 (20 days), T5 (25 days) and T6 (30 days) were used in this study. The effect of different mushroom varieties and composted period of sawdust showed significant variation in growth and yield parameters. The results revealed that the highest number of the fruiting body, the effective fruiting body and biological yield were found in V2, whereas the lowest numbers were observed in V3. Besides, the maximum yield, the highest number of fruiting bodies and effective fruiting body were observed in T3. Moreover, the maximum yield (56.50 g) was produced by V2T3 combination, and the minimum yield (38.13g) was produced by V3T2. The highest biological efficiency (32.28 %) was obtained in V2T3, whereas the lowest biological efficiency (21.78%) was obtained in V3T2 sawdust. This study suggests that Pleurotus ostreatus and 15 days composted sawdust showed the best performance.