The slower and longer release of fertilizers by coating them with polymers is extremely important in terms of both economic and prevention of environmental pollution. Chitosan produced from waste crayfish shells was preferred in the current study because of its biological origin and environmental friendliness, and was used for the coating of 15-15-15 fertilizer.Glutaraldehyde was used as a crosslinker for the coating of 15-15-15 fertilizer with chitosan.In the study, the coating of fertilizers at different concentrations was tried and the carrying capacity of chitosan for 15-15-15 fertilizer was determined. Powder samples produced after coating were characterized using Fourier transform infrared spectrometry (FT-IR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) techniques. Then, the degradation rates of the coated fertilizers in the soil were determined depending on the days. Considering all the obtained results, it has been revealed that chitosan-15-15-15 fertilizer formulation crosslinked with glutaraldehyde can be used practically in agricultural and horticultural applications.