Background Evidence from the USA and elsewhere has linked smoking depictions in movies with youth smoking initiation. Prior research has not focused on depictions in films produced in the Middle East, however.

Objective We reviewed the 10 most commercially successful Iranian films released each year over three decades (1982–2011) to determine trends in depictions of tobacco use over time.

Methods Each movie was reviewed in its entirety, and depictions of smoking were recorded and classified as direct (characters holding or using tobacco products) and indirect (tobacco products appearing in the frame, but not being used). Time trends in average duration of direct, indirect and total smoking depictions were analysed using linear regression and Cohen's κ coefficient.

Results The mean duration of tobacco depictions in the most commercially successful Iranian films fluctuated yearly over the 3 decades, but with an overall significant upward trend (p<0.005). The proportion of movies depicting tobacco consumption during the three decades was 36% (1982–1991), 60% (1992–2001) and 74% (2002–2011), respectively. The average proportion of total movie time for these depictions (0.75%, 1.41%, 2.08%) increased significantly (p<0.005) over the 3 decades as did the average duration of smoking depictions,(39.1, 67 and 99.3 s, respectively, p<0.005).

Conclusions The significant increase in the proportion of movies depicting tobacco consumption and in the duration of smoking depictions over the past 30 years underscores the need for increased regulation of the Iranian film industry to minimise this important source of influence on tobacco initiation in young people.