A pretest-posttest control group experimental design was used to evaluate the effectiveness of EnvisionIT, a 10-unit web-based curriculum designed to teach secondary students information technology (IT) skills in the context of transition-planning activities. Fifteen high schools were stratified by socioeconomic status and randomly assigned to the EnvisionIT experimental condition or a control condition in which students received traditional instruction. Pre- and posttest data for 287 students--119 (41%) of whom had disabilities--were analyzed using hierarchical linear modeling. Findings indicated that students in the experimental group made significantly greater gains in IT literacy than students in the control group. Students in the experimental group also showed greater gains in several transition skills, including goal setting, knowledge of how to find jobs, and information about college. Results support the conclusion that the EnvisionIT curriculum produces improvements in students' acquisition of the 21st-century skills needed for success in today's high tech world. (Contains 3 tables.)