To clarify the relevance of prolactin (PRL) to clinical parameters in patients who visited our general medicine department, medical records of 353 patients in whom serum PRL levels were measured during the period from 2016 to 2018 were retrospectively reviewed. Data for 140 patients (M/F: 42/98) were analyzed after excluding patients lacking detailed records and patients taking dopaminergic agents. Median serum PRL levels were significantly lower in males than females: 6.5 ng/ml (IQR: 4.2-10.3) versus 8.1 ng/ml (5.9-12.9), respectively. Pain and general fatigue were the major symptoms at the first visit, and past histories of hypertension and dyslipidemia were frequent. Male patients with relatively high PRL levels (≥ 10 ng/ml) had significantly lower levels of serum albumin and significantly higher levels of serum LDH than those with low PRL (< 10 ng/ml). There were significant correlations of male PRL level with the erythrocyte sedimentation rate (R=0.62), serum LDH level (R=0.39) and serum albumin level (R=-0.52), while the level of serum CRP (R=0.33) showed an insignificant but weak positive correlation with PRL level. Collectively, these results show that PRL levels had gender-specific relevance to various clinical factors, with PRL levels in males being significantly related to inflammatory status.