The ridgelet transformation was introduced as a sparse expansion for functions on continuous spaces that are smooth away from discontinuities along lines. Focusing on the face detection problem, a novel face detection method using ridgelet transform and BP neural network was proposed. Two stages are involved in this method. Firstly, the pretreated face images are decomposed by the ridgelet transformation. Then the corresponding ridgelet coefficients are set as the input samples for a well-designed BP neural network. The good results are thus obtained.