Aims: This study aimed to determine if the children's leisure activities impact the presence of pathogens on their hands and toys. Methods & Results: To assess the microbiological hazard in playground areas, a pilot study that included 12 children was conducted. We then conducted an intervention study; children's hands and toys were washed before playing. Faecal coliforms, pathogenic bacteria and Giardia lamblia were quantified by membrane filtration, selective media and flotation techniques, respectively; rotavirus, hepatitis A and rhinovirus by RT-PCR. Pilot study results revealed faecal contamination on children's hands and toys after playing on sidewalks and in public parks. Pathogenic bacteria, hepatitis A and G. lamblia on children's hands were also found. In the intervention study, Staphylococcus aureus and Klebsiella pneumoniae were found on children's hands at concentrations up to 2.5 x 10(4) and 1 x 10(4) CFU hands(-1), respectively. E. coli and Kl. pneumoniae were detected on toys (2.4 x 10(3) and 2.7 x 10(4) CFU toy(-1), respectively). Salmonella spp, Serratia spp and G. lamblia cysts were also present on toys. Conclusion: Children's play activities influence microbial presence on hands and toys; the transfer seems to occur in both ways. Significance and Impact of the Study: Control strategy needs to be implemented to protect children from infectious diseases.