Objective: The objective of this project was to test the short term (90 days) efficacy of an automated behavioural intervention for smoking cessation, the "1-2-3 Smokefree" programme, delivered via an internet website.

Design: Randomised control trial. Subjects surveyed at baseline, immediately post-intervention, and 90 days later.

Settings: The study and the intervention occurred entirely via the internet site. Subjects were recruited primarily via worksites, which referred potential subjects to the website.

Subjects: The 351 qualifying subjects were notified of the study via their worksite and required to have internet access. Additionally, subjects were required to be over 18 years of age, smoke cigarettes, and be interested in quitting smoking in the next 30 days. Eligible subjects were randomly assigned individually to treatment or control condition by computer algorithm.

Intervention: The intervention consisted of a video based internet site that presented current strategies for smoking cessation and motivational materials tailored to the user's race/ethnicity, sex, and age. Control subjects received nothing for 90 days and were then allowed access to the programme.

Main outcome measures: The primary outcome measure was abstinence from smoking at 90 day follow up.

Results: At follow up, the cessation rate at 90 days was 24.1% (n = 21) for the treatment group and 8.2% (n = 9) for the control group (p = 0.002). Using an intent-to-treat model, 12.3% (n = 21) of the treatment group were abstinent, compared to 5.0% (n = 9) in the control group (p = 0.015).

Conclusions: These evaluation results suggest that a smoking cessation programme, with at least short term efficacy, can be successfully delivered via the internet.