<p>Prolactin has a wide range of biological functions, including regulation of cognition. However, there are few studies on the relationship between prolactin and cognition in schizophrenia. A total of 113 patients with schizophrenia were included in this study. Serum prolactin concentrations were collected and MATRICS consensus cognitive battery (MCCB) was used for cognitive assessment. Eighty-four of one hundred and thirteen patients (74.3%) had hyperprolactinemia. There was no significant difference in the incidence rate of hyperprolactinemia between different sex (<i>χ</i>² = 1.57, <i>p</i> = 0.21), but the serum prolactin concentration of female patients was significantly higher than that of male patients (median = 676.5mIU/L for male and median = 1178 mIU/L for female, <i>Z</i> = 2.53, <i>p</i> = 0.001). Inverse U-shaped relationships were found between prolactin and brief visuospatial memory test-revise (BVMT-R) (<i>F</i> = 4.008,&#xa0;<i>p</i> = 0.021); and Hopkins verbal learning test-revised (HVLT-R) (<i>F</i> = 5.857,&#xa0;<i>p</i> = 0.004). Prolactin may have a mixed effect on cognition depending on its concentration and mild elevated prolactin level&#xa0;is beneficial for cognitive performance in schizophrenia.</p>