Introduction of a sugar tax on sugar-sweetened beverages (SSBs) has been proposed by peak health bodies and Australian politicians as a strategy to control behaviour that leads to obesity. The question is: what are the implications of imposing a sugar consumption tax on SSBs with the aim to curb the harmful effects of obesity? Arguments for and against a sugar consumption tax pose an ethical dilemma. While evidence supports the implementation of a sugar consumption tax as effective in curbing SSB consumption within certain populations, ethical considerations support the premise that autonomy trumps justice, beneficence, and non-maleficence. Legal implications include the consideration of Commonwealth and State jurisdiction, discrimination against a person's disability, such as obesity, and infringement on consumer rights. Alternative strategies should be considered to address obesity, including social action, education and information, and use of the media.