We have developed an efficient method for the preparation and maintenance of primary cell cultures isolated from adult Mnemiopsis leidyi, a lobate ctenophore. Our primary cell cultures are derived from tissue explants or enzymatically dissociated cells, and maintained in a complex undefined ctenophore mesogleal serum. These methods can be used to isolate, maintain and visually monitor ctenophore cells to assess proliferation, cellular morphology and cell differentiation in future studies. Exemplar cell types that can be easily isolated from primary cultures include proliferative ectodermal and endodermal cells, motile amebocyte-like cells, and giant smooth muscle cells that exhibit inducible contractile properties. We have also derived 'tissue envelopes' containing sections of endodermal canal surrounded by mesoglea and ectoderm that can be used to monitor targeted cell types in an in vivo context. Access to efficient and reliably generated primary cell cultures will facilitate the analysis of ctenophore development, physiology and morphology from a cell biological perspective.