Research capability and the teaching pipeline are seriously threatened by the global drop in the number of students pursuing PhD degrees. There is still a lack of consensus across disciplines and theoretical stances about the intricate decision-making process that shapes intentions for PhD study. The present systematic review aims to synthesize elements affecting doctorate study palns, focusing on the Theory of Planned Behaviour (TPB) and provide a thorough theoretical lens that allows to analyze this significant educational option. In accordance with PRISMA, 45 research articles that had been released between 2000 and 2023 and were accessible through four databases (Scoups, ERIC, PsycINFO, and Web of Science) were examined. Empirical investigations into factors influencing doctorate study plans among prospective or current master’s grads or students were taken into consideration while determining the selection requirements. The results suggest that the most crucial determinant of students’ intents to pursue a doctoral degree is their mindset regarding their motifs of pursuing a doctoral at academic institutions (attitudes towards doctorate’s studies), particularly their intrinsic desire and love for researching. The next most significant indicators are self-efficacy, money related issues, and a sense of behavioral control. Although subjective norms are important, their impact varies depending on the society. The three TPB constructs work together rather than against each other.