Hypertension, diabetes mellitus and obesity play a crucial role in mediating ill-health, and are commonly seen in postmenopausal women. The objective of this study was to explore the possibility that a person’s risk of developing hypertension, diabetes or obesity can be influenced by their ABO blood type, Rhesus factor or both, among postmenopausal females. This cross-sectional study covered randomly selected 201 postmenopausal women, mean age 53.5±6.6 (±SD) years, from Port Harcourt, Rivers State, Nigeria. Blood glucose, blood pressure and body mass index measurements and ABO/Rhesus blood groups of all the participants were determined and correlated for each other. Analysis of the data revealed that in the ABO/rhesus blood system, the prevalence of hypertension , diabetes mellitus and obesity was 43.3%, 38.8% and 13.9%, which 14.4% versus 13.2%, 13.9% versus 13.2%, and 5.0% versus 4.0% are associated with O versus B rhesus positive blood groups respectively and are invariably higher than other blood groups. Data analysis further revealed a complex and positive association thus: hypertension comorbidly occurred with diabetes (21.5%), overweight (20.9%), normoglyceamic (18.9%), normal body weight (13.0%), obesity (9.4%) and prediabetes (2.9%) respectively. Additionally, diabetes combined with overweight (20.4%), prehypertension (12.6%), obesity (9.4%), normal body weight (9.0%) and normotension (4.7%). More so, obesity coexisted with prediabetes (4.5%) and/or prehypertension (4.5%). Correlation analysis revealed that the incidence and prevalence of hypertension, diabetes or obesity risk for blood group O subjects are in the order of the ratio 1:1 compared with subjects having B blood group.