The present investigation on “Influence of organic manures on yield parameters of guava (Psidium guajava) cv. Lucknow 49” was conducted in a farmer’s field located at Suthamalli village under Ariyalur District, Tamil Nadu during 2023-24. The study aimed to evaluate the application of organic manures, specifically combinations of farmyard manure, vermicompost, poultry manure, and neem cake significantly enhanced the yield parameters of guava cv. Lucknow 49 compared to untreated control conditions. The field experiment was laid out in randomized block design in three replications with fourteen treatments. The treatments were designed by combination of FYM, vermicompost, poultry manure and neem cake at different levels. The results of the present study indicated that the yield parameters  viz., number of flowers/tree (162.16 and 173.36), number of fruits/tree (151.97 and 163.52), fruit set percentage (93.71 % and 94.32%), fruit length (6.71 and 6.98 cm), fruit diameter (6.89 and 7.10 cm), fruit weight (189.22 and 193.27 g) and yield/tree (29.83 and 34.18 kg) was found to be the highest in two successive crops, the treatment which received soil application of FYM 10 kg + vermicompost 5 kg + poultry manure 2.5 kg + neem cake 5 kg/tree followed by vermicompost 5 kg + poultry manure 2.5 kg + neem cake 5 kg/tree. The least values for all the yield parameters were noticed in the untreated control.