Abstract The occurrence of 28 pharmaceuticals and personal care products (PPCPs) was investigated in 17 surface water samples (rivers, canals, and lagoons), 12 groundwater samples (wells and boreholes, which can also be consumed for drinking) and 8 drinking water samples (bottles and sachets) during dry and rainy seasons in Lagos state, Nigeria. The most prevalent compound detected in all samples was amoxicillin (an antibiotic) at median concentrations of 1614, 238 and 358 ng/L in surface water, ground water and drinking water, respectively. This is of concern due to potential impact on development of antibiotic-resistant microbial strains. Other frequently-detected compounds include acetaminophen, nicotine, ibuprofen, and codeine with detection frequencies of more than 70%. Investigation of seasonal variability revealed that glyburide, caffeine, naproxen and diclofenac concentrations were significantly (P