Background Although doctors increasingly engage in online information seeking to complement their medical practice, little is known regarding what online information sources are used and how effective they are. Objective Grounded on self‐determination and needs theory, this study posits that doctors tend to use online information sources to fulfil their information requirements in three pre‐defined areas: patient care, knowledge development and research activities. Fulfilling these information needs is argued to improve doctors' perceived medical practice competence. Methods Performing PLS‐SEM analysis on primary survey data from 303 medical doctors practicing in four major Greek hospitals, a conceptual model is empirically tested. Results Using authoritative online information sources was found to fulfil all types of information needs. Contrarily, using non‐authoritative information sources had no significant effect. Satisfying information requirements relating to patient care and research activities enhanced doctors' perceptions about their medical practice competence. In contrast, meeting knowledge development information needs had the opposite result. Discussion Consistent with past studies, outcomes indicate that doctors tend to use non‐authoritative online information sources; yet their use was found to have no significant value in fulfilling their information requirements. Conclusions Authoritative online information sources are found to improve perceived medical practice competence by satisfying doctors' diverse information requirements.