To understand the distribution and formation of chlorophenols (CPs) and bromophenols (BPs), we analyzed water and sediment samples collected from the riverine areas and the marine environments near a nuclear power plant (NPP) in Korea. In the seawater, only BPs (2,4-dibromophenol and 2,4,6-tribromophenol) were detected, while CPs and BPs (4-chlorophenol, 2,6-dichlorophenol, 2,4,6-trichlorophenol and 2,4,6-tribromophenol) were detected in the riverine water. 2,4-DBP (0.531-32.7 ng/L) in the seawater was detected in sites near the NPP and 2,4,6-TBP (0.378-20.2 ng/L) was found in most of the seawater. In the riverine water, the sample near the industrial complex (118 ng/L) showed a greater total concentration than others (0.510-7.64 ng/L). In the marine sediments, BPs (99.0-553 ng/g dry weight) showed higher concentrations than CPs (0.145-16.1 ng/g dry weight). The BPs levels (1.01-8.55 ng/g dry weight) in the riverine sediments were much lower (10-500 times) than those in the marine sediments. The distribution patterns of CPs and BPs between the marine and riverine environments differed, with relatively high levels of BPs appearing in the marine environments due to natural formation except for anthropogenic sources. The chlorination process of the NPP also seems to form BPs (2-bromophenol, 2,4-dibromophenol and 2,4,6-tribromophenol). However, the effluents had an influence on the seawater near the NPP (about 2 km). In the riverine environments, CPs were dominant, which are related to the industrial complex. Thus, CPs and BPs in the marine and riverine environments are generated via various routes such as anthropogenic formation and biosynthesis.