Nephrocytes are cells involved in the regulation of the composition of the hemolymph and are characterized by peripheral finger-like projections delimiting a labyrinthine channel system. We have combined structural and immunological methods to examine the spatial distribution of microtubules and microfilaments in disseminated nephrocytes of Ceratitis capitata larva; the nephrocytes are scattered among the fat-body cells, close to the salivary glands. Actin filaments are localized in two discrete peripheral domains and microtubules are mostly concentrated in the cortical region. We discuss the possibility that these cytoskeletal elements, localized in the finger-like processes of the plasma membrane, are involved in maintaining the spatial architecture of the cell periphery and in modifying the junctional complexes that represent the entrance to the labyrinthine channel system.