Melanophores from tadpoles of Xenopus laevis (Daudin) were isolated by digestion of tail fins with acetyltrypsin and collagenase and maintained in primary culture for 6 weeks up to 3 months. Within 36 to 72 h the melanophores develop one to eight dendritic processes per cell; secondary and tertiary branchings of the processes were frequently observed. The melanophores in primary culture disperse under the influence of alpha-MSH or cyclic AMP; upon rinsing out these substances the cells aggregate. In darkness, about 40% of the cells disperse their pigment, whereas under illumination the pigment of the melanophores aggregates. To date, attempts to initiate cell division in melanophores have not been successful.