The steroidogenic profiles of the corpora lutea and the remaining ovarian tissue from the snake Storeria dekayi at early and midpregnancy were compared after incubation with [4-14C] pregnenolone. Both tissues produced the following metabolites identified by their isopolarity and isomorphicity with standard compounds: 17α-hydroxypregnenolone, progesterone, 11-deoxycorticosterone, androstenedione, and testosterone. The steroids 17α-hydroxyprogesterone and dehydroepiandrosterone were not detected. Integration of the yield-time curves showed that much more 11-deoxycorticosterone and progesterone were synthesized by the corpora lutea at both stages of pregnancy than by the remaining ovarian tissue, whereas the latter produced more androstenedione and testosterone. Steroid 21-hydroxylase activity was almost exclusively confined to the luteal tissue. The corpora lutea at midpregnancy were smaller but showed greater steroid-converting activity per unit weight of tissue than those at early pregnancy. It is suggested that 11-deoxycorticosterone secretion may be involved in the function of the corpus luteum which is, supposedly, essential for embryonic survival during early pregnancy in some viviparous snakes.