Exercise-induced bronchospasm (EIB) is a transient narrowing of the airway that usually occurs shortly after exercise. It is a clinical entity that has been reported among school children. With the global increase in prevalence rate of asthma and other allergic disorders, there is a likelihood that the prevalence of EIB may have also increased. If this condition is undetected and untreated, it may limit exercise performance and quality of life of an individual. This study aimed to determine the prevalence, clinical features and socio-demographic factors associated with exercise-induced bronchospasm among secondary school children aged 10 to 17years. This is a school-based descriptive cross-sectional study which employed a multistage sampling technique. Subjects were recruited over a period of nine months. A total of 265 students were studied from six secondary schools (two public and four private schools) in Osogbo town. Informed consent was obtained from the caregivers of all the students prior to the study. The demographic data, socio-economic class, risk of allergies, clinical examination findings and FEV1 measurements were recorded. The diagnosis of EIB was made when there is a decrease in FEV1 of ≥10% after exercise. Of the 265 students studied 138 (52.1%) were females and 127 (47.9%) were males giving a male to female ratio of 0.9: 1. Their age (Mean ± SD) was 13.4 ± 1.9 years. Thirty-four (12.8%) of the 265 students had exercise induced bronchospasm (EIB) with a decrease in FEV1 measurement of ≥10% after exercise, thus the prevalence of EIB among the subjects was 12.8%. Ten (29.4%) of the 34 students with exercise induced bronchospasm belong to the 13 years age group. The gender distribution showed that EIB occurred more commonly in females than males; however this difference was not statistically significant (p- value of 0.634). The students with low socioeconomic class were observed to have the highest frequency of exercise induced bronchospasm; but this was not statistically significant (p- value of 0.081). The most common symptom reported by the subjects as associated with exercise prior to the free running exercise was fatigue. Other symptoms include: cough, shortness of breath, chest tightness, wheezing and muscle cramp. Shortness of breath has the highest sensitivity of 52.9% but a low specificity of 31.6%. Wheezing has low sensitivity (2.9%) but a high specificity of 100%. History of recurrent brownish itchy eyes, recurrent itchy throat and sniffing were associated with increased occurrence of EIB and this association was statistically significant (p- value < 0.001, 0.006 and 0.016 respectively). This study has demonstrated that the prevalence of EIB among school children in Osogbo was 12.8%; it is commoner among the 13 years age group and those belonging to the lower socioeconomic class. History of allergic conjunctivitis and rhinitis are associated with occurrence of EIB. Symptoms suggestive of EIB is however not diagnostic of the condition. It is therefore important that free running test and objective lung function test should be performed using a spirometer particularly among children with features of allergy. This will facilitate early diagnosis and management of EIB in children.