Rice is the major cereal crop of Bangladesh, but its production remains insufficient to fulfill the demand of the population. Prolonged applications of imbalanced and chemical fertilizer degrade soil fertility particularly in coastal areas which results in low yields. Therefore, the present experiment was carried out at the field of Agriculture Department, Noakhali Science and Technology University (NSTU), Noakhali-3814, from December 2022 to May 2023 to investigate the effects of organic and inorganic fertilizers on the growth, yield and yield contributing traits of Boro rice. The experiment comprised three treatments viz., T0 = Control, T1 = 50% NPKS + 50% cowdung (3 t ha-1), T2 = 75% NPKS + 25% cowdung (1.5 t ha-1), T3 = 100% NPKS. The experimental design employed a Randomized Complete Block Design (RCBD) with three replications. The highest plant height (117.4 cm), number of tillers per hill (15.83), panicle length (24.16 cm), number of grains per panicle (111.57), straw yield (7.6 t ha-1), 1000 grains weight (25.27g), grain yield (7.5 t ha-1), and harvest index (49.24%) was obtained from T2 which comprised of 75% NPKS + 25% cowdung (1.5 t ha-1) whereas the lowest value was obtained from control. Thus, this particular dose may be ideal for Boro rice production, enhancing growth, yield, and yield-contributing characteristics in coastal zones of Bangladesh.