Personal digital assistants (PDAs) are versatile task organizers that hold promise as assistive technologies for people with cognitive-behavioral challenges. This delayed randomized controlled trial compared two groups of adult workers with autism spectrum disorder (ASD) to determine whether the use of an Apple iPod Touch PDA as a vocational support improves work performance and reduces personal support needs on the job. Baseline data were collected on 50 adults with ASD who were beginning a vocational placement supported by a job coach. Participants were randomized to receive training in the use of a PDA as a vocational aid upon starting their job or after working 12 weeks without PDA support. Workers who received PDA training at the beginning of their job placement required significantly less hours of job coaching support (p = 0.013) during their first 12 weeks on the job than those who had not yet received the intervention. Functional performance between the two groups was not significantly different. The significant difference in hours of job coaching support persisted during the subsequent 12 weeks, in which both groups used a PDA (p = 0.017).