Dietary supplementation with omega-3 fatty acids (N-3) has been widely recommended because of the global preference for Western-style diet which is rich in omega-6 fatty acids (Wang et al, 2008). Therefore, we investigated the effects of N-3 and/or metformin in male diabetic Wistar rats. It was hypothesized that the co-administration of N-3 and metformin would not have significant effect on bone mineralization markers in diabetic state. Twenty-five rats (N=5) (Average weight: 120 g) were divided into the following: control; diabetic untreated; diabetic + N-3; diabetic + metformin and diabetic + N-3 + metformin. Diabetes was induced by the administration of streptozotocin (65 mg/kg b.w., i.p.), 15 min after the administration of nicotinamide (110 mg/kg b.w., i.p.) (Masiello et al., 1998). Five days afterwards, N-3 and metformin were administered daily at 200 and 180 mg/kg b.w., p.o. respectively for four weeks (Adeyemi and Olayaki, 2018), after which the rats were sacrificed under ketamine anaesthesia (50 mg/kg, i.m.). Data were analysed using analysis of variance and Turkey post hoc test at p<0.05. The results showed that the induced diabetes was accompanied with significant increases in calcium to phosphorus ratio (Ca:P) and tartrate acid phosphatase (TRAP), but significant decreases in parathormone and phosphorus. Relative to diabetic untreated, treatments with N-3 and metformin caused significant elevations in total alkaline phosphatase (TALP), osteocalcin, parathormone, oestrogen and calcium; however, a significant decrease in TRAP. Co-administration of N-3 and metformin showed more desirable effects on TALP, c-terminal telopeptide of type 1 collagen (CTX-1), oestrogen and Ca:P compared to single administration. There was no significant difference in the effects of N-3 relative to metformin in all the biomarkers, with the exception of Ca:P, where metformin had a more favourable effect. In conclusion, co-administration of N-3 and metformin could be preferably used in the maintenance of bone health diabetic state.