Neural crest cells from the cranial region of chick embryos were cultured in the presence of fetal calf serum in which they differentiate into melanocytes or in the presence of horse serum in which they differentiate into neuron-like cells. Undifferentiated cultures, as well as pigmented and neuronal cultures, incorporated [14C]proline into types I and III collagen and into non-collagenous proteins. When cells differentiated into melanocytes, the ratio of collagen to non-collagenous protein did not change. In contrast, in cultures where a portion of the cells differentiated into neuron-like cells, the ratio of collagen to non-collagenous protein was reduced. Indirect immunofluorescence studies using specific antibodies against collagen or procollagen types I, II, III, and IV demonstrated that undifferentiated neural crest cells, melanocytes and neuron-like cells stained only with antibody to type III procollagen, while fibroblastic cells present in some cultures stained only with antibody to type I procollagen. Our results demonstrate that although the types of collagen synthesized by neural crest cells do not change with time in culture, the relative amounts of collagen may reflect the pathway of differentiation of the cells.