Recent trends in achievement test scores among elementary and secondary school students in Iowa are examined. Form 7 of the Iowa Tests of Basic Skills (ITBS) was used to measure the achievement of students in grades 3 and 7; and Form X-7 of the Iowa Tests of Educational Development (ITED) was used for 11th graders. These grade levels were chosen because they correspond most closely to the age groups for which the disturbing results were received from the National Assessment of Educational Progress (NAEP). ITBS scores of Iowa third and seventh graders in 1978-79 were compared with those of students in the same grades in 1984-85; ITED scores of 11th graders from 1979-80 and 1985-86 were likewise compared. At each grade level in each of the selected school years, data for over 5,000 students were analyzed. Findings of the study are somewhat at odds with those of the NAEP. Specifically, the Iowa study indicated that: (1) although increases in scores are generally greater for low-scoring students, high-scoring students in Iowa showed substantial improvements across the years; (2) no practical differences appeared in the changes in performance for higher-level versus lower-level skills; and (3) students' performance increased on all types of items. Discrepancies with the NAEP study may have resulted from typically higher achievement test scores by Iowa students, the general lack of uniformity of achievement score trends, and differences in data analysis. Twelve data tables are included. (TJH)