The study was designed to determine the contribution of standardized scored inspections implemented during the Athens 2004 Pre-Olympic and Olympic period, in assessing the presence of Legionella spp. in water sites. Inspection grading scores of 477 water supply systems, 127 cooling towers and 134 decorative fountains were associated with the corresponding microbiological test results of 2514 samples for Legionella spp. Nine violations of water supply systems and nine of cooling towers significantly associated with positive microbiological test results, and four violations of water supply systems and one of cooling towers were among those designated as 'critical' water safety hazards in the inspection reports. The study documents a strong correlation [water supply systems (RR 1.92), cooling towers (RR 1.94)] between unsatisfactory inspection scoring results and Legionella-positive microbiological test results (in excess of 10,000 c.f.u./l) and suggests the utility of inspection scoring systems in predicting Legionella proliferation of water systems and in preventing Legionnaires' disease.