Introduction: Nasal mucociliary clearance is an important physiological function of nasal cavity that helps in protecting the lower respiratory tract from undesirable organic and inorganic matter including the micro organisms. The study was designed to establish normal mucociliary clearance time in healthy children in a tropical environment. Material and methods: The study was carried out in 100 randomly selected normal school children aged 4-15 years using saccharin method. The diseases that are known to affect the nasal mucociliary clearance were excluded. The study variables were age and sex. Results: Mean nasal mucociliary clearance time was 5.7+/-2.59 min with no significant difference between males and females. The clearance time was found to be impaired in groups A and B including children of 4-7 and 8-11 years of age respectively. Conclusion: Nasal mucociliary clearance is impaired in children of either sex between 4 and 11 years probably due to subclinical adenoiditis. However clearance returns to normal level at the time of puberty, which coincides with adenoids involution.