Cocaine use and addiction are common and problematic. Within the past year, 1.3M people had a cocaine use disorder and 20,000 people died of cocaine overdose (NSDUH 2020). The present study had three goals. First, the same behavioral test can produce different results in different laboratories (Crabbe et al., 1999). We hoped to establish conditioned place preference (CPP) for cocaine in our laboratory mice, that was consistent with CPP reported by other laboratories. Second, response to many drugs, such as cocaine, can differ based on biological sex (Becker & Chartoff 2019). We wanted to identify sex differences in cocaine-induced locomotion and cocaine CPP. Third, females’ hormonal status can affect cocaine CPP and cocaine self-administration (Calipari et al., 2017, Johnson et al., 2019). We wanted to evaluate whether females’ estrus stage correlated with the strength of cocaine CPP. The CPP apparatus was composed of two chambers, one with white walls and grid flooring and the other with black walls and bar flooring. During the pre-conditioning session, mice passed freely between the chambers, to identify pre-existing chamber biases; the difference in time spent in each chamber was very small in both males and females. For the conditioning phase, mice were pseudorandomly assigned to receive cocaine (10mg/kg) or saline in each chamber, in an unbiased design (Cunningham et al., 2006). During each conditioning session, mice were injected with cocaine or saline before being placed in that chamber for 30min. Conditioned preference for the cocaine- and saline-paired chamber was then assessed. Both females and males showed an overall preference for the cocaine-paired chamber. The strength of this preference was consistent with existing literature. Control mice conditioned with saline in both chambers did not show an overall preference for either chamber, as expected. Cocaine also elevated locomotor activity during cocaine conditioning sessions; there were no sex differences in this cocaine-induced response. Estrus samples are currently being analyzed. Together, our findings revealed conditioned place preference for cocaine in both sexes, that is consistent with existing literature.