How technology affects learning has been at the centre of recent debates over educational inputs. In 1994, the Israeli State Lottery sponsored the installation of computers in many elementary and middle schools. This programme provides an opportunity to estimate the impact of computerisation on both the instructional use of computers and pupil achievement. Results from a survey of Israeli school-teachers show that the influx of new computers increased teachers’ use of computer- aided instruction (CAI). Although many of the estimates are imprecise, CAI does not appear to have had educational benefits that translated into higher test scores.