 The reliability and validity of research instruments are essential components of any successful study. Reliability refers to the consistency of measurements over time, while validity assesses whether the instrument accurately measures the constructs it was designed to measure. Various forms of reliability and validity exist, such as internal consistency, test-retest reliability, concurrent validity, and predictive validity. This paper provides a brief literature review on the importance of reliability and validity in medical science. This article was authored by Ishtiak Ahmed and Sinda Ishtiak.