Abstract: An incubation study was conducted to assess the effect of composted tea leaves, coffee waste and kitchen garbage on the kinetics of net nitrogen mineralization and P, K, Ca and Mg availability. NH4-N, NO3-N, Bray II P, the exchangeable cations, EC and pH were determined after 0, 7, 14, 21, 42 and 63 day. Inorganic N concentration in the amended soils was analyzed by a first-order model. The pH of the soil increased after 14-21 day of incubation and gradually decreased thereafter. EC values showed the following trend: composted tea leaves > kitchen garbage > coffee waste. The composts were highly variable in their N mineralization characteristics, but the peaks for mineralized N content were observed at early incubation times in all the composts, i.e., after 14-21 day because the composts had undergone maturation. Potential respective mineralizable N (N0) content of the composted tea leaves, coffee waste and kitchen garbage was 18.8, 6.30 and 22.4 mg kg-1 dry soil and the respective rate constant (k) was 0.101, 0.199 and 0.255 day-1. Rate of N mineralization for the composted tea leaves, coffee waste and kitchen garbage was 5.25, 9.10 and 38.6%, respectively, of the total N content. Composted kitchen garbage displayed the highest value for N release rate. P, K and Ca showed the following trend: composted tea leaves > kitchen garbage > coffee waste and Mg was composted tea leaves > coffee waste > kitchen garbage.