Recent studies have shown that learning and memory capacity is disturbed in depressive patients, and it is important to reveal the effects of antidepressant drugs on cognitive function in depressive patients with memory problems. Citalopram, a selective serotonin reuptake inhibitor (SSRI), is one of the most widely used drugs for the treatment of disorders related to serotonergic dysfunction like depression and anxiety. Contradictory findings exist regarding the effects of SSRIs on memory. The aim of this study is to investigate whether citalopram affects memory in various models of learning and memory tasks in rats. Citalopram (at 20 and 50 mg/kg) significantly shortened the retention latency in the passive avoidance test and prolonged the transfer latency on the second day at 10 and 50 mg/kg doses in the elevated plus-maze test. Citalopram also significantly increased the number of errors (at the 10 mg/kg dose) and prolonged the latency values compared to the control group in both reference and working memory trials in the three-panel runway test. Citalopram also impaired reference memory trials of animals at the 20 mg/kg dose. In conclusion, citalopram impaired cognitive performance in passive avoidance, elevated plus-maze and three-panel runway tasks in naive rats. These effects might be related to serotonergic and nitrergic mechanisms, which need to be investigated in further studies.