Colleges and schools are institutions helping to educate people and give them knowledge. To take the best of it, students should consider it seriously. The co-educational system has its drawbacks that certainly have a negative impact on a student, especially on the religious and moral development. Coed colleges and schools bridge the gap that is usually found among girls and boys by changing their behaviours and morals. Girls started to lose their shyness due to long hours spent with boys. They started to imitate some boys' attributes, such as speaking loudly. They also imitated boys in their clothing and hairstyle so as to make it impossible to differentiate them from a distance. On the contrary, some boys adopt a more feminine way of speaking and show excessive concern for themselves. Islam has played an active role in governing the relationships between men and women. It governs marriage and has banned adultery and anything which may lead to it: looking, touching, wearing tight clothes for girls etc... Some girls, forgetting that they came to receive an education, set their heart on being beautiful so as to be admired by boys. In order to prevent such things to occur, colleges should have separate institutions for boys and girls. To bypass the negative impact of the coed system, it would be much better to separate the two sexes. To conclude, the coeducational system has a negative impact which has led some writers to call for a separation of boys and girls within education to facilitate better academic results.