In 2007, public school students in Puerto Rico at grades 4 and 8 participated in a Spanish-language version of the National Assessment of Educational Progress (NAEP) in mathematics. A representative sample of approximately 2,800 students from 100 public schools was assessed at each grade. This report contains performance results on NAEP mathematics questions for public school students in Puerto Rico and the nation. At grade 4, the average of the question scores for students in Puerto Rico was lower than the score for students in the nation overall and within each content area. There was no statistically significant difference in performance between male and female students in Puerto Rico overall and in each content area. At grade 8, the overall average of the question scores for students in Puerto Rico was lower than the score for students in the nation. Results were similar for each content area. While there was no significant difference between the performance of male and female students in Puerto Rico overall, male students had a higher score than female students in the measurement content area, and female students had a higher score than their male peers in the data analysis and probability content area. The report includes appendix of tables, listing the NAEP 2007 mathematics questions for grades 4 and 8 that were released to the public after the assessment. They are organized by content area and increasing order of difficulty for students in Puerto Rico. (Contains 12 figures and 6 tables.)