Objective To explore the relevances of serum prolactin level to clinical symptoms and disease activities of systemic lupus erythematosis (SLE). Methods From December 2008 to December 2014, 63 female patients who met the American Rheumatism Society diagnostic criteria of SLE in the First People’s Hospital of Chengdu were collected as the SLE group, and other 20 healthy females were collected as the control group. The serum prolactin level was determined by immunofluorescence, and the disease activity of SLE was assessed by SLE Disease Activity Index (SLEDAI). The relevances of serum prolactin level to clinical symptoms and disease activity of SLE patients were analyzed. Results The mean serum prolactin level was (22.35±14.86) ng/mL in the SLE group and (15.30±8.54) ng/mL in the control group, respectively; the difference was statistically significant (P<0.05). In the 63 SLE patients, 15 (23.8%) had higher serum prolactin level compared with the normal ones. According to the SLEDAI score, the SLE patients were divided into stable group (25 patients), mild activity group (21 patients), moderate activity group (10 patients), and severe activity group (7 patients); and their serum prolactin levels were (20.43±11.23), (22.50±13.54), (27.97±21.20), and (33.91±18.18) ng/mL, respectively; the differences were not statistically significant (P>0.05). There were statistically significant differences (P<0.05) between the SLE patients with hyperprolactinemia and the ones with normal serum prolactin level in a number of clinical symptoms such as serositis, kidney damage,hematological system damage, and hypocomplementemia, but the serum prolactin level was not significantly correlated with the SLEDAI (rs=0.217, P=0.088). Conclusions Less hyperprolactinemia is found in SLE patients. Serum prolactin level is correlated with multiple clinical symptoms and laboratory indexes but not related to disease activity in SLE patients.