This study researches the effects of cold joint on the direct tensile and flexural strength of the concrete. The experimental studies were carried out on C25 concrete samples produced according to the standard TS EN 206-1. Cold joints were formed at the angles of 45 and 90 degrees in the concrete samples, which were produced in the shape of a 100x200 mm cylinder and a 100xl00x500 mm prism. Test samples were prepared first by pouring the half of the concrete samples and forming the cold joint after waiting 2, 3, 4 and 6 hours, and then by pouring the remaining half of the concrete. Direct tensile and flexural strength tests were conducted on these samples. The results showed that during the formation of cold joint, a longer period of time led to a decrease on the direct tensile and flexural strength of the concrete. This decrease was more evident on the concrete samples poured after 6 hours.