This study was designed to assess the effect the summer vacation period has on the reading ability of first-grade subjects, as measured by norm- and criterion-referenced reading tests. The data were analyzed to determine if sex of subject, IQ, or type of school reading curriculum were related to the ability to retain overall reading ability or specific reading skills. Subjects in the study were 311 first-grade pupils enrolled in nine northeastern Wisconsin elementary schools. Approximately one-half of the subjects were enrolled in an objective-based reading program while the remaining subjects were enrolled in basal reader curricula. It was concluded that sex of subject, intellectual ability, and type of school reading curriculum do not appear to be important variables related to the retention of overall reading ability and specific reading skills. While significant losses were found on 11 of the 14 measures, when the data were examined in terms of percentage of subjects considered to have mastered the skills in the spring and fall, only 15 percent of the subjects needed to be recategorized. (Author/RB)