BACKGROUND: Asthma causes significant morbidity and mortality in the developing world. It is thus important to identify modifiable risk factors. OBJECTIVES: To undertake a cross-sectional study to determine the prevalence of skin test reactivity to aeroallergens in Jamaican children and adults and the relationship of the diagnosis of asthma to the pattern of skin test positivity. METHODS: One hundred and sixty subjects without the sickle cell gene (genotype AA), eighty adults and eighty children, were recruited. Skin testing to seven aeroallergens was undertaken (atopy being diagnosed if there were at least one positive reaction). Asthma status was determined by a questionnaire and/or medical records. RESULTS: Twenty-seven (34%) of the children and forty-one (51%) of the adults were skin test positive to at least one aeroallergen. The most common positive responses in both age groups were to Dermatophagoides farinae, Dermatophagoides pteronyssinus and cockroach mix-(German and American). All adult asthmatics with current symptoms reacted to cockroach allergen. CONCLUSIONS: Appropriate steps to reduce cockroaches and cockroach sensitization might positively impact on asthma morbidity in Jamaica.