Composites are subjected to different working environments when they are employed. In this study, the bearing strength and failure modes of composite-pinned joints subjected to various types of environments for different exposure times are investigated, experimentally. The specimens were divided into five categories which include cold environment, hot environment, humid environment, seawater environment, and room temperature. The test results were carried out after 1 and 2 months of exposure to different environmental conditions. A total of 540 test specimens with 20 different geometries were fabricated for the pin-bearing experiments. Two different geometrical parameters were investigated during analysis. The ratio of edge-distance-to-hole diameter and the ratio of the specimen width-to-hole-diameter were systematically varied and corresponding failure modes and loads were defined. The performance of the joints is closely related to changing in geometrical parameters. It was observed that different environment conditions did not change failure modes consisting of net tension, shear-out, bearing, and mixed, generally. Also, the experimental results show that the bearing strength of composite-pinned joints is affected at different levels when subjected to environmental conditions for various exposure times.