The effects of a voluntary summer reading intervention with and without a parent training component were evaluated with a sample of low-income Latino children from language minority families. During the last month of 4th grade, 370 children were pretested on a measure of reading comprehension and vocabulary and were randomly assigned to (a) a treatment group in which children received 10 self-selected books during summer vacation, (b) a family literacy group in which children received 10 self-selected books and were invited with their parents to attend 3 summer literacy events (2 hr in length), and (c) a control group. Although children in the treatment group and the family literacy group reported reading more books than the control group, there was no significant effect on reading comprehension and vocabulary. Recommendations for improving the efficacy of the intervention are discussed, including efforts to improve the match between reader ability and the readability of texts and the instructional goals of the family literacy events. (Contains 8 tables.)