This study examined the influence of operational practices on supply chain resilience at the Kenya Medical Supplies Authority (KEMSA). In view of recurrent public health emergencies, strengthening supply chain resilience is essential for national health security preparedness. Anchored in resilience theory, the study employed a convergent mixed-methods research design. Data were collected from 115 questionnaire respondents and 15 key informants, achieving a 100% response rate. Quantitative data were analysed using descriptive and multiple regression analysis, while qualitative data were analysed thematically. The findings indicate a moderate level of supply chain resilience (Supply Chain Resilience Index = 2.97/5) and a relatively high implementation of operational practices (Supply Chain Operational Practices Index = 3.31/5). The regression model explained 53% of the variation in supply chain resilience (R² = 0.53, p < .001). Supplier management emerged as the strongest predictor of resilience (β = 0.41, p < .001), followed by inventory control and policy compliance (β = 0.27, p < .001), system coordination and digitization (β = 0.23, p = .001), governance and control (β = 0.19, p = .008), and demand planning and forecasting (β = 0.16, p = .026). Applying resilience theory, the study demonstrates that operational practices collectively determine the ability of health supply chains to anticipate, absorb, and recover from disruptions. The study concludes that strengthening operational practices enhances supply chain resilience and recommends supplier diversification, improved data integration, stronger governance mechanisms, and enhanced inventory management to improve health system preparedness.