During the past few decades, significant increase in the consumption of coffee has led to rapid increase in the production of coffee waste in South Korea. Spent coffee waste is often treated as a general waste and is directly disposed without the necessary treatment. Spent Coffee Grounds (SCGs) can release several organic contaminants, including caffeine. In this study, leaching tests were conducted for SCGs and oxidative degradation of caffeine were also conducted. The tested SCGs contained approximately 4.4 mg caffeine per gram of coffee waste. Results from the leaching tests show that approximately 90% of the caffeine can be extracted at each step during sequential extraction. Advanced oxidation methods for the degradation of caffeine, such as UV/H₂O₂, photo-Fenton reaction, and UV/O₃, were tested. UV radiation has a limited effect on the degradation of caffeine. In particular, UV-A and UV-B radiations present in sunlight cause marginal degradation, thereby indicating that natural degradation of caffeine is minimal. However, O₃ can cause rapid degradation of caffeine, and the values of pseudo-first order rate constants were found to be ranging from 0.817min^-1 to 1.506 min^-1 when the ozone generation rate was 37.1 g/㎥. Additionally, the degradation rate of caffeine is dependent on the wavelength of irradiation.