KEY FINDINGS: Research philosophy has been introduced to offer an alternative way to think about problem-driven research that is normally conducted. To clarify the research philosophy, four research paradigms, i.e. positivism (or empiricism), postpositivism (or realism), interpretivism (or constructivism) and pragmatism, are investigated according to philosophical realms, i.e. ontology, epistemology, axiology and logic of inquiry. With the application of research philosophy, some examples of quantitative and qualitative research were elaborated along with the conventional research approach. Understanding research philosophy is crucial for pharmacy researchers and pharmacists, as it underpins the choice of methodology and data collection.