Humic acid (HA) forms from organic matter decomposition and influences pepper fruit yield and quality. One of the important quality parameters in pepper fruit is antioxidant compounds and the interest in the consumption of pepper fruit is primarily a result of its content of dietary antioxidants. In this study the effects of foliar and soil HA fertilization on antioxidant properties of organically grown pepper fruit under greenhouse conditions were determined. Pepper plants were treated with soil and foliar HA applications at different concentrations (0, 10, 20, 30 and 40 ml/l). HA was applied to the plants by way of both spraying and drenching to the plant root area three times during the vegetation period at 15-day intervals. Antioxidant activity in the hydrophilic (HAA) and lipophilic (LAA) fractions, lycopene, beta-carotene, total phenolic compounds and chlorogenic acid contents were determined from each treatment The results showed that HA application significantly improved antioxidant compounds in pepper fruit and this effect was mainly on carotenoids and phenolic compounds.