The school had a population of about 300 students. Information came from reports from teachers regarding discrepancies between the daily attendance sheet and actual class attendance and from office records on students who signed out as sick. Results revealed no obvious correlations between student absences and the subject being taught, in contrast to findings in the United Kingdom. Student absences increased rapidly during the day. Afternoon absences were particularly prevalent among senior students. Further analysis revealed that certain groups of students regularly left school; many were achieving below their full academic potential. They included a group of senior nonacademic females who had older male friends and parentally approved lunch passes; a group of persistent truants, who usually attended school for only one or two periods per day; students with documented difficulty attending school regularly due to illness or low self-esteem; and occasional truants. Many of the students were truant together. Findings from this and other studies suggested procedures that schools can use to address this serious and largely unreported form of truancy. Tables, photograph, and 15 references