OBJECTIVE: To examine the impact of plain packaging of cigarettes with enhanced graphic health warnings on adolescents' perceptions of pack image and perceived brand differences. METHODS: Cross-sectional school-based surveys conducted in 2011 (prior to introduction of new cigarette packaging) and in 2013 (7-12 months afterwards). Students aged 12-17 years (2011 n=6338; 2013 n=5915) indicated whether they had seen a cigarette pack in previous 6 months. Students rated the character of four popular cigarette brands, indicated level of agreement regarding differences between brands in ease of smoking, quitting, addictiveness, harmfulness and look of pack; and indicated positive and negative perceptions of pack image. Changes in responses of students seeing cigarette packs in the previous 6 months (2011: 60%; 2013: 65%) were examined. RESULTS: Positive character ratings for each brand reduced significantly between 2011 and 2013. Changes were found for four of five statements reflecting brand differences. Significantly fewer students in 2013 than 2011 agreed that 'some brands have better looking packs than others' (2011: 43%; 2013: 25%, p<0.001), with larger decreases found among smokers (interaction p<0.001). Packs were rated less positively and more negatively in 2013 than in 2011 (p<0.001). The decrease in positive image ratings was greater among smokers. CONCLUSIONS: The introduction of standardised packaging has reduced the appeal of cigarette packs. Further research could determine if continued exposure to standardised packs creates more uncertainty or disagreement regarding brand differences in ease of smoking and quitting, perceived addictiveness and harms.