In this report we describe the expression of p68, which is believed to be an important regulator of protein synthesis, in various tissues during normal human fetal development. Conventional, formalin-fixed paraffin-embedded sections of normal organs from human fetuses ranging from 9 to 42 weeks of gestation were immunostained with the monoclonal antibody TJ4C4 utilizing a conventional avidin-biotin complex procedure. The expression of p68 could be detected in many cell types arising in most of the tissues examined within the time period of fetal development studied. p68 expression was most frequently seen, and most intensely expressed in respiratory epithelium, urothelium and ependyma. Expression in other tissues was more variable. These data show that there is regulated expression of p68 in a wide variety of tissues during normal fetal development which parallels the known expression of this protein in normal and neoplastic adult tissues.