This study investigated information sharing and use of health care workers in primary health care centres in Oyo State, Nigeria. The descriptive survey research design of the correlational type was adopted for the study. The population of the study comprised 1787 health care workers spread across 33 primary health care centers (PHCCs) in the headquarters of the Local Government Areas (LGAs) in Oyo State, Nigeria. Sample size of 631 was used for the study and questionnaire was used for data collection. Findings from the study revealed work related issues, problem solving, provision of forum for discussion of ideas and exchange for a reward as major purposes for which primary health care workers in PHCCs Oyo State, Nigeria shared information among themselves just as a high level of information sharing was established amongst them. Also, findings from the study established major purposes of information use by the health care workers as including performance of difficult and technical tasks, helping to influence others to translate vision into action, to come up with unique ideas and to adapt, and work with colleagues and other stakeholders in the sector. On the frequency of use of information by the health care workers, the study revealed occasional use but a positive significant relationship was established between information sharing and use. The study recommended the provision of relevant information management facilities such as computers and related technologies by the management of primary healthcare centres in Oyo State, Nigeria for effective information sharing and use among the primary healthcare workers.