Information is presented on the composition of the 1979 membership of the American Institute of Physics (AIP). Questionnaires were administered to members of the nine independent societies of the AIP to determine demographic and employment information. Background characteristics of the membership include the following: more than half identify themselves as physicists; Ph.D.s predominate among the membership; only 5 percent are females; only 8 percent are members of specified minority groups; nearly 90 percent are employed full-time; and slightly more than half are nonacademically employed with industry being the predominant nonacademic employer. Information on type of employment by degree received is also presented. While research, both basic and applied, is the major work activity, many are also involved in teaching, development, design and engineering, and administration. Nearly two-thirds of AIP society members are currently working in physics and astronomy. Information is also presented on subfield of current work and correlated to highest degrees. After salary data, comparisons are made between the nine societies on selected characteristics. The nine societies comprising the AIP are: American Physical Society; Optical Society of America; Acoustical Society of America; The Society of Rheology; American Association of Physics Teachers; American Crystallographic Association; American Astronomical Society; American Association of Physicists in Medicine, and American Vacuum Society. (SW)