Background Older adults are prone to obesity and metabolic abnormalities and recommended to pursue a normal weight especially when obesity and metabolic abnormalities are co-existed. However, few studies have reported the possible differences in the effect of obesity on outcomes between older adults with metabolic abnormalities and those without metabolic abnormalities. Methods A total of 3485 older men were included from 2000 to 2014. All-cause mortality and cardiovascular mortality were obtained during a mean follow-up of five years. Metabolic abnormalities were defined as having established hypertension, diabetes, or dyslipidemia and taking the disease-related medications. All participants were stratified by the presence or absence of metabolic abnormalities. Results In the non-metabolic abnormalities group, all-cause and cardiovascular deaths were lowest in overweight participants and highest in obese participants. In the metabolic abnormalities group, mortality was also lowest in overweight participants but highest in participants with normal weight. After adjustment for covariates, hazard ratios (95% CI) for all-cause death and cardiovascular death were 0.68 (0.51, 0.92) and 0.59 (0.37, 0.93), respectively, in overweight participants with metabolic abnormalities. Furthermore, obesity was not associated with mortality risk in both groups. These findings were unchanged in stratified analyses. Conclusions Overweight was negatively associated with mortality risk in older men with metabolic abnormalities but not in those without metabolic abnormalities. Obesity did not increase death risk regardless of metabolic abnormalities. These findings suggest that the recommendation of pursuing a normal weight may be wrong in overweight/obese older men, especially for those with metabolic abnormalities.