The effect of hands-on laboratory activities on secondary student learning was examined. Assessment was conducted over a two-year period, with 262 students participating the first year and 264 students the second year. Students took a prequiz, performed a laboratory activity (gas chromatography of alcohols, or photosynthesis and respiration), and followed up with a postquiz. The percentage of correct answers on the pre- and postquiz was tallied for each student and each question. A paired t-test was performed to detect differences in scores. Student scores increased significantly after both laboratory activities both years (p less than 0.001). For each gas chromatography of alcohols quiz question, a significant increase was observed the second year (p = 0.041), but not the first year (p = 0.11). For each photosynthesis and respiration quiz question, a significant increase was observed the first year (p = 0.038), but not the second year (p = 0.066). However, when one specific photosynthesis and respiration quiz question was omitted, both years showed a significant increase (first year, p = 0.0064; second year, p = 0.039). Overall, these results indicate laboratory activities provided by science outreach programs can positively contribute to student learning. (Contains 3 tables and 4 figures.)