The 1990 National Postsecondary Student Aid Study (NPSAS:90) is the second in a series of federally funded surveys of enrolled postsecondary students. Its key purpose is to portray accurately the characteristics of these students, particularly recipients of student aid. Results will answer questions about recipients and sources of federal and private aid and parental support. The NPSAS surveys also provide base information on cohorts that will be the subjects of study over time. Data from the survey can be used for more advanced statistical and economical analyses. The NPSAS:90 used a three-stage sampling technique to select participants (schools and students), and a two-phase data collection method of record abstracting to compile student records from student and parent telephone interviews and data from institutions. In all, 1,130 institutions participated, and 70,200 students were sampled. The executive summary contains 16 tables of student and institutional characteristics, and there are 23 other tables in the body of the report. Twenty-six figures and exhibits illustrate the discussion. Five appendixes present sample material mailed to sampled institutions and students, analysis variables' specifications, procedures used for data imputations, standard errors for estimates in the executive summary, and memos on weighting procedures and a description of the 1987 NPSAS sample. (SLD)