Abstract Purpose – The aim of this paper is to contribute to sustainable development in higher education by exploring the online information behaviour (OIB) of first-year full-time PhD students. In the case of first year PhD students, there is a high demand for information to complete their tasks and to finalise their studies. The quality of the education these postgraduate students acquire is dependent on their ability to access quality information devoid of barriers. In other words, there seems to be a lack of research on the online information behaviour of postgraduates in their first year of doctoral studies. Design/methodology – The study examined this phenomenon through the case study method, using the interpretivism paradigm and the quantitative approach. Using convenient and purposive sampling methods, 10 first-year PhD students were sampled from the University of Ghana's student population for 2023. A structured interview schedule was used as the instrument for data collection from the participants of the study. Findings – First-year PhD students are faced with online information-seeking barriers such as poor internet connectivity, limited access to online databases and resources, inability to access the needed paid online resources due to financial constraints, information overload, difficulty in acquiring requisite information and lack of information literacy skills and financial resources. These challenges tend to influence the quality of education they receive negatively given the inequalities in their information literacy skills against the literacy skills of second to final-year PhD students. Practical Implications and Conclusion – The study will contribute to literature on the information-seeking behaviour of first-year PhD students. The lack of information on the subject in Ghana is an issue this study seeks to address. The study has shown that postgraduate students at the University of Ghana do not understand their information needs, although they depend heavily on information for their work and survival.