This is the third annual survey of total graduate and postdoctoral enrollment in science and engineering in the United States. Data elements collected from 7,505 departments of 355 Ph.D.-granting institutions include: enrollment status (full and part-time); level of study (first year and beyond first year); citizenship; sex of students; type institution (public or private); and distribution among areas and fields of engineering and science. Data trends are reported for the period 1967-1974. Findings include: science enrollment in graduate programs increased 6% between 1973 and 1974; every science area, except mathematics, showed an expansion; full-time students holding assistantships rose 4%; students receiving Federal support declined 3%; female enrollment in full-time graduate science programs increased 13%; and full-time foreign student enrollment declined 3%. Detailed statistical tables are included. (SL)