The existing disconnect between the design and practical implementation of the infection control policy within healthcare facilities has not been properly defined, even though it has severe consequences on the patient safety. This research thus examined the correlation existing between the fidelity of implementation of infection control systems and the contamination results in different hospital wards with different risk levels of classifications. The design was a cross-sectional correlational design across ten inpatient wards of a tertiary care hospital of two high-risk intensive care units, three medium-risk surgical wards, and five low-risk general medical wards. Fidelity of implementation was measured by a WHO-based, observational checklist and environmental contamination was measured by microbiological samples and rates of healthcare-associated infections were measured through institutional surveillance data. Statistical tests were Pearson correlation analysis, multiple regression analysis, and ANOVA. The implementation scores had strong negative correlations with the environmental contamination (r = -0.927, p < 0.001) and HAI rates (r = -0.915, p < 0.001). The hand hygiene compliance and the frequency of surface cleaning became the most predictive independent variables and jointly predicted the infection rates by 91.8%. Significant effects on the implementation fidelity were not noticed between risk strata (p = 0.637). These results indicate that implementation fidelity is important to infection control system efficacy and that hand hygiene and environment cleaning are priority areas of intervention.