Introduction Soil transmitted helminths are among the neglected tropical diseases prevalent in developing countries, and children are the most vulnerable. The objective of the cross—sectional study was to determine the prevalence and intensity of soil—transmitted helminths (STHs) in preschool and school aged children in Ile-Ife and Ekiti.

Methods Faecal samples (511) were collected between May and July 2010 and processed using modified Kato - katz technique.

Results The overall prevalence of STH infection was 29.2%. Ascaris lumbricoides (28.4%) was the most prevalent, and were observed; 136 (26.6%) either alone or together with Trichuris trichiura and/or hookworm infections. Prevalences of A lumbricoides ranged from 6.7% to 47.5%, T trichiura from 1.3 to 4.9% and hookworms from 0.5 to 4.9% in the four schools. The prevalences of A lumbricoides, T trichiura and hookworms were 28.4, 3.1 and 1.8% respectively. Intensity determined by egg count per gram of faeces (epg) ± SEM were 939.84 ± 122.62 for A lumbricoides, 0.03 ± 0.01 for T trichiura and 0.02 ± 0.01 for hookworm. There was no significant difference between sex and prevalence of A lumbricoides. The prevalence of A lumbricoides rose from 8.1% in children aged 2–3 years and reached the peak (75.0%) in children 12 years and above.

Conclusion The findings from this study showed that STH infections are endemic in the schools investigated and urgent interventions involving both preschool and school children such as deworming and health education are recommended.