In this study, a new method is presented for face recognition by using DCT-faces that are calculated by the 3 dimensional Discrete Cosine Transform (3D DCT). In this method, firstly, face images in the database are collected on top of each other and then 3D DCT is applied to this 3D structure. Then 2D Inverse DCT of each coefficient layer is calculated separately. After this operation, DCT-faces are found which are very similar to eigenfaces. By taking the inner product between DCT-faces and original face images, feature vectors are calculated to be used in face recognition. Experimental results show that, the face recognition ratio of DCT-faces is close to that of eigenface method. Moreover, the proposed method has a lower time complexity and lower memory complexity.