The aims of the study were to identify the types, determine the extent of community pharmacists' involvement, and evaluate the factors influencing their participation in public health activities in Nigeria. The study was a cross-sectional survey of randomly selected 130 registered community pharmacies. Pretested questionnaire was the instrument for data collection. Descriptive and inferential statistics were used to analyse data. Response rate was 94.9%. The study identified 31 types of public health activities which community pharmacists participated in. Their extent of involvement was highest in patient counseling (4.93 ± 0.25), personal hygiene (4.90 ± 0.37), maintenance of normal blood pressure (4.88 ± 0.32), and techniques for using vagina pessaries (4.85 ± 0.38). Lowest areas of involvement were elimination of smokeless tobacco use (2.27 ± 1.56), use of seat belts when driving (2.03 ± 1.46), and the need to live in a safe neighborhood (1.42 ± 0.53). Inadequate training (96%), lack of pharmacists' time (94.6%), inadequate personnel (92.3%), lack of patients' time (88.5%), lack of profit (85.4%), inadequate space in the pharmacy (82.3%) and inadequate patients' information (69.9%) significantly influenced their participation. The study concluded that community pharmacists would participate more in public health activities if the identified barriers are reduced.