Introduction In April 2010, the Australian government became the first to announce legislation mandating that tobacco products be sold in plain packaging. The announcement generated significant media coverage and public feedback. The increased readership of and community commentary on online news present an opportunity to assess the range of arguments most likely to be used by opponents to this policy.

Methods A content analysis was conducted of reader commentary posted on Australian online news items about the plain packaging announcement. Reader opinion polls on the plain packaging were also recorded. All arguments opposed to plain packaging contained within reader comments were categorised into 11 debating frames.

Results Of 117 relevant news items, 41 included 1818 reader comments. 1187 (65.3%) comments contained no reference to plain packaging, and mainly addressed a tobacco tax rise announced at the same time. The comments about plain packaging were more than 2.5 times more likely to oppose than support the policy. The dominant argumentative frame, comprising 27% of oppositional comments, was that plain packaging would be ineffective in reducing smoking. Online reader poll results showed equal support for and opposition to plain packaging.

Conclusions The results of this study can be used by tobacco control advocates to anticipate opposition and assist in reframing and counteracting arguments opposed to plain packaging.