Pharmaceutical care and medicines management are terms which are often used interchangeably to describe the patient-centred services provided by pharmacists. The programme of research presented within this thesis evaluated a range of topics within this area of endeavour. The extent of pharmaceutical care provision within the community pharmacy setting was examined in a cross-sectional survey in N. Ireland and across 15 European countries. The findings indicated that community pharmacists' provision of comprehensive pharmaceutical care can be deemed as limited in Northern Ireland (mean score 41.4% of the total achievable score) and across Europe (scores ranged from 56.6% in England to 29.4% in Moldova). To inform the development of a definitive RCT for novel post-discharge medicines management clinic (MMC), a feasibility study was carried out, and identified a number of methodological challenges, in particular, challenges around patient recruitment, attrition rates and clinic scheduling. A series of risk assessment models was developed to help with the targeting of patients to be recruited for the RCT referred to above. These models were designed to forecast the likelihood of patient early readmission to hospital (within 30 and 8 to 30 days) and high-cost readmissions. Important risk factors for readmission identified included the Charlson age-adjusted co-morbidity score, respiratory- and genitourinary-related primary diagnoses and number of medications prescribed on discharge, and new patient targeting criteria for the RCT to explore the impact of the MMC was developed. A systematic content analysis revealed that the print media coverage of medicine-related adverse effects requires significant improvement in order to properly inform the public on this matter. Specifically, the reporting of adverse effects, in terms of medicines implicated and organ systems affected, did not correspond with those commonly cited in scientific journal articles. Findings from the present research help contextualise and provide evidence based advice on a number of issues which need to be addressed in pharmaceutical care / medicines management practice and research.