We report a 7-year-old pediatric patient with an apparently self-limiting, subacute miliary pneumonitis that occurred 6 weeks after a near-drowning accident in shallow, muddy water. After biopsy, histological examination revealed aspirated foreign bodies (algae and pollen grains) in the affected lung areas and a foreign body reaction in the form of a granulomatous inflammation. The lack of any detectable infectious agents suggested a causative role of these aspirated algae and pollen grains in the development of lung disease.