Lake Van fish (Alburnus tarichi Guldenstadt 1814) is the only fish that can adapt to the extreme conditions (pH 9.8 salinity 0.2% and alkalinity 151.2 meq/L) of Lake Van. In this study, it was aimed to determine the cytotoxic and genotoxic effects of chlorpyrifos (CPF) on Lake Van fish primary gill cell culture. Gill epithelium from Lake Van fish was isolated enzymatically and grown in primary culture on Leibovitz's L-15 medium. After different doses (0.01, 0.1, 1, and 10 μM) of CPF were applied to the gill cells, the total oxidant status (TOS), total antioxidant status (TAS), malondialdehyde (MDA), and DNA damage levels (8-hydroxyguanine (8-OHdG)) were examined at the end of 24 and 48 h. It was determined that the TOS, MDA, and 8-OHdG levels increased in the cells exposed to high doses (1 and 10 μM) of CPF and the TAS was decreased (P < 0.05). It was revealed from this study that CPF administered at a dose higher than 1 μM can cause oxidative stress and DNA damage in the primary gill cell culture of Lake Van fish. In addition, the findings showed that Lake Van fish primary gill cell culture was useful in determining the effects of toxic substances likely to be the contaminants of a lake.