Background. Evidence shows that obesity negatively influences children's physical, physiological and musculoskeletal well-being. Objectives. This study examined the relationship between triponderal mass index (TMI), blood pressure (BP), and musculoskeletal fitness (MSF) in a cross-sectional sample of school children in Ado-Ekiti, Southwest Nigeria. Methods. Body weight, stature, systolic and diastolic blood pressures (SBP & DBP), and three components of musculoskeletal fitness, comprising sit and reach (SR), sit-up (SUP), standing broad jump (SBJ), and 20-meter shuttle runs, were assessed in 1229 (boys=483, 39.3%; girls=746, 60.7%) school children (age range: 9-13 years). Results. A significant positive correlation was found between TMI and SBP (r= 0.182, P < 0.01), and DBP (r= 0.090, P < 0.01), while TMI and SR (r= -0.067, P < 0.05) and SBJ (r= -0.246, P < 0.01) yielded a substantial inverse relationship. Children with severe underweight were significantly less probable to perform well in SBJ (OR= 0.96, CI= 0.94; 0.99) and 20-meter shuttle run (OR= 1.39, CI= 1.22; 1.61). Childhood overweight was associated with increased SBP (OR= 1.03, CI= 1.02; 1.05) and poor SBJ (OR= 0.98, CI= 0.97; 0.99). Obese children were significantly associated with increased SBP (OR= 1.04, CI= 1.02; 1.06), poor SR (OR= 0.92, CI= 0.87; 0.98) and SBJ (OR= 0.94, CI= 0.93; 0.96) scores compared to age-and sex-specific norms. Conclusion. Elevated BP and poor musculoskeletal fitness could adversely affect the well-being of undernourished, overweight, and obese Nigerian children. Findings implicate the need to implement dietary and physical activity intervention programs to promote desirable health-related quality of life in school-going children.