Introduction: Many patients with kidney disease are asymptomatic but may have abnormalities in urine. The aim of this study was to determine the prevalence of urinary abnormalities (UA) in asymptomatic secondary school children in Calabar, Nigeria and its relationship with age, sex, social class,  body mass index and blood pressure. Methodology: It was a descriptive cross sectional study of 407 apparently healthy secondary school children aged  10-18 years recruited by multistage sampling techniques in June-July, 2022. Semi-structured questionnaires were used to obtain their bio-data and clinical  history. Subject’s height and weight were measured using a stadiometer and body mass index (BMI) calculated. Blood pressure of each subject  was measured using auscultatory method. Early morning urine was obtained from each subject and urinalysis done using dipstick- combi 10. The result  of urinalysis was recorded. Data were analyzed using SPSS version 22.0 and p- value ≤ 0.05 was significant. Results: Out of 407 participants,  162 (39.8%)  were males and 245 (60.2%) females giving a M:F ratio 1:1.5. The mean age was 13.5 ± 1.9 years. The prevalence of urinary abnormalities was 115 (28.3%)  with many having more than one abnormality. Age group 13-15years were more commonly affected. Nitrituria 75(18.4) was the most frequent urinary  abnormality followed by proteinuria 38 (9.3%), leucocytes14 (3.4%) andhaematuria 5(1.2%). There was no glucosuria. Nitrituria was statistically significant  among females (p=0.040). Blood pressure, overweight and obesity were not statistically significant in relation to urinary abnormalities. Conclusion: The  prevalence of urinary abnormalities was high among secondary school children but commoner in females and mainly nitrituria, proteinuria, leucocytes  and haematuria. We therefore recommend regular screening for urinary abnormalities among secondary school children in our environment for early  detection and prevention of renal diseases