Purpose To examine the frequency of hyperprolactinemia and the socio-demographic, clinical, and quality of life (QOL) correlates. The frequency of prolactin-related side effects and associated subjective experiences were also examined. Methods A cohort of 1364 psychiatric inpatients were consecutively recruited and evaluated. Basic socio-demographic and clinical data were collected. Psychopathology, prolactin-related side effects were measured using standardized instruments. QOL was assessed using the Medical Outcomes Study Short Form 12. Results The frequency of hyperprolactinemia was 61.3% in the whole sample; 61.6% in female and 60.8% in male patients. There was no significant association between hyperprolactinemia and any QOL domain. In the whole sample, 15.1% of patients reported moderately severe breast symptoms and lactation, and 53.9% reported moderate or severe discomfort. Nearly a third of female patients (30.4%) reported at least moderate menstrual changes and 50.2% moderate or severe discomfort, while 24.2% of male patients reported at least moderate erectile dysfunction and 52.6% moderate or severe discomfort. Multiple logistic regression analysis revealed that patients with hyperprolactinemia were less likely to be married, diagnosed with mood disorders, or treated with clozapine, aripiprazole, or antidepressants but more likely to receive risperidone. Conclusions Effective measures to lower the frequency of hyperprolactinemia and the related side effects should be considered in Chinese psychiatric facilities.