The purpose of this study was to determine the effects of absenteeism and intra-city mobility on academic achievement; specifically, reading and mathematics, in an integrated, urban Michigan School District. Besides percent of absenteeism and rate of intra-city school mobility, the district school records which were utilized as the data base of the study included the following related factors: Metropolitan Achievement Test (MAT) scores, socio-economic status, sex and ethnic group. Examination of these additional variables broadened the study focus. The population was a stratified random sample of 515 sixth grade students. Categories of student mobility for the two-year study were: zero school changes, one school change, and two or more school changes. Students included in the attendance sample had to have absentee levels of: (1) 0-1% (0-2 days), (2) 6-7% (11-13 days), and (3) 15% (27 days) or more and their absenteeism could not vary (+OR-)3% over the two-year period. Socio-economic status (SES) was determined by identifying students associated with free and reduced lunch program (below SES) as opposed to those who were not in this program (average or above SES). Hypotheses were analyzed by univariate one-way analysis of variance in order to further verify the results of the ex post facto data. Findings indicated that: (1) students with average or above SES consistently scored higher on the MAT test than students with below average SES; (2) students with two or more school changes during the two-year period of the study scored lowest on the MAT achievement test; (3) students with high levels of attendance scored better on the test; (4) male and female students scored equally well on the test; and (5) White students, however, scored higher on the MAT than Black and Latino students. There were significant differences in performance on the MAT among students with different levels of absenteeism; that is, students of average and above SES having high levels of absenteeism showed statistically high losses in academic achievement while students of below average SES showed significantly lower achievement levels in the MAT scores, regardless of attendance level. This may indicate that attendance levels by themselves, without other enrichment, did not increase achievement for below average SES students. It was recommended that school personnel be trained to utilize the available student data to define the nature and level of the supportive services needed to increase academic achievement. In addition, school systems with predictably high numbers of dropouts, truants and mobile students should use trained volunteers to provide supportive services to this needy student population. Schools should develop in-service training to provide employees with the necessary skills to train parents to communicate and understand their child's problems. Emphasis should be placed on the need for continuity in at least one area of the child's life--the school. Mid-year school changes should be discouraged if feasible or reasonable. School systems should survey levels of absenteeism and mobility of Black and Latino students to determine cause of low academic achievement; they should become interested in conducting surveys of these students' parents to determine why they feel their children are achieving poorly. School district research departments could design a computer program for rapid identification of students with high mobility and absentee rates. School systems might consider a uniform curriculum with basic textbooks and a projected timeline for completion of each basic skill subject area, by grade level, to ensure better instructional continuity for highly mobile students.