A simple method is presented for establishing continuous cell lines from Drosophila melanogaster embryos. Subculturing is performed after the first 8 weeks and at 2-week intervals thereafter. Initial plating densities of 5 x 10(4) to 5 x 10(5) cells per cm2 are required for maintaining the subcultures. Cell lines were established from wild-type embryos, from embryos bearing chromosomal rearrangements and from embryos bearing recessive mutations. Permanent lines have doubling times of 24 to 48 hr and have been maintained for as long as 13 months and 25 subcultures.