OBJECTIVES: Pharmacy Value Added Services (PVAS) was introduced as a matter of public health policy by the Malaysia’s Ministry of Health to improve health outcomes through public healthcare services. However, adoption rates are low and therefore hampering the achievement of national health policy goals. Our objective is to explore the key determinants and mediators of successful implementation of new public pharmaceutical services by investigating the cognitive perspectives of patients’ intentions to adopt with the Theory of Planned Behavior as the theoretical framework. METHODS: A two phase mixed methodology involving first a qualitative exploration and the second a quantitative phase was conducted in public health facilities in Negeri Sembilan, Malaysia. Multiple regression and mediation analysis were performed. RESULTS: Subjective norms, perceived behavioural control, knowledge and expectations are found to be significant predictors of intentions to adopt PVAS. Knowledge and expectations are found to exert significant indirect effects on intentions. CONCLUSIONS: Overall, we suggest that patient knowledge be enhanced through appropriate channels and expectations of service quality be met to increase intentions. Our results are robust and suggests that a bottom-up approach should be key to successful implementation of health policies and services.