While mass media campaigns have been shown to contribute to reductions in smoking prevalence, little research has been undertaken on the effectiveness of radio advertising as a communication medium. This is despite radio being less expensive and having greater reach than television in some low and middle income countries. We aimed to explore the potential of radio as an adjunct or alternative to televised campaigns by comparing reactions to a radio anti-smoking ad with three televised anti-smoking ads, all of which communicated the serious health consequences of smoking in an emotionally evocative way. In pre-exposure interviews, 18-59-year-old daily smokers (n = 306) were asked to listen to a particular radio time slot/watch a particular television program that they usually listened to/watched, in which the ad was broadcast. Post-exposure interviews were conducted within 3 days of exposure and measured recall, recognition, emotional and cognitive responses, and intentions to quit smoking. Findings indicate that the radio ad showed similar or slightly higher levels than a concurrently aired television ad on understanding (radio: 96%; television: 95%), believability (radio: 89%; television: 90%), concern about smoking (both 77%) and motivation to quit (radio: 51%; television: 45%), and significantly higher levels of unprompted recall (radio: 20%; television: 6%). It also compared well against two subsequent anti-smoking television ads. Emotionally evocative radio advertising may be an effective adjunct or alternative to television advertising in jurisdictions where there are substantial limits on funds available for airing these campaigns, or where the reach of radio outstrips television.