Background: Swimming is a recreational activity generally considered to be a healthy exercise. However, swimming pools may transmit a great number of infectious diseases, if not properly maintained, disinfected and monitored. The objective of the research was to investigate the water quality of Isfahan swimming pools and comprise the results with the standards. Methods: Twenty-five of public swimming pools were surveyed. Water samples were examined for physiochemical parameters including temperature, turbidity, pH and free chlorine and also for heterotrophic plate count (HPC) bacteria, total and fecal coliforms, fecal streptococci, Staphylococcus aureus and Pseudomonas aeruginosa. Findings: There was a poor compliance to the established standards for two important physiochemical parameters, including free chlorine and pH. Among the microbial indicators, total coliforms were the most frequent isolate, followed by HPC and fecal coliforms the next. The correlation analyses demonstrated the HPC and total coliforms bacteria populations increased with decrease in free chlorine. The correlation analyses also indicated that there was a positive relationship between total coliforms and all other microbiological parameters. Conclusion: Complete compliance of the pools to the standards was fairly poor and only one of the pools was free of pollution by fecal coliforms and P. aeruginosa, two important microbial indicators, during the sampling period. It is also important to maintain the proper level of free chlorine and pH in the swimming pools to ensure safety of the water quality. Keywords: Swimming pools, Water quality, Microbial indicators, Standard.