In 1990, the National Assessment of Educational Progress (NAEP) included a Trial State Assessment (TSA); for the first time in the NAEP's history, voluntary state-by-state assessments were made. The sample was designed to represent the 8th grade public school population in a state or territory. In 1996, 44 states, the District of Columbia, Guam, and the Department of Defense schools, took part in the NAEP state science assessment program. The NAEP 1996 state science assessment was at grade 8 only, although grades 4, 8, and 12 were assessed at the national level as usual. The 1996 state science assessment covered three major fields: earth, physical, and life sciences. In Nevada, 133 students in 8 nonpublic schools. Results were not reported for public schools because of low participation level. This report describes the science proficiency of Nevada eighth-graders, compares their overall performance to students in the West region of the United States and the entire United States (using data from the NAEP national assessment), presents the average proficiency for the three major fields, and summarizes the performance of subpopulations (gender, race/ethnicity, parents' educational level, Title I participation, and free/reduced lunch program eligibility). To provide a context for the assessment data, participating students, their science teachers, and principals completed questionnaires which focused on: instructional content (curriculum coverage, amount of homework); delivery of science instruction (availability of resources, type); use of computers in science instruction; educational background of teachers; and conditions facilitating science learning (e.g., hours of television watched, absenteeism). On the NAEP fields of science scales that range from 0 to 300, Nevada nonpublic school students had an average proficiency of 159 compared to 162 for nonpublic school students throughout the United States. In Nevada, the average science scale score of students attending nonpublic schools (159) was not significantly different from that of nonpublic school students across the nation (162). (DDR/NB)