Little is known about the effectiveness of subtitles in cross‐cultural advertising messages. In an experimental study, we analyzed the advertising effectiveness of (non‐)subtitled English‐only TV commercials for different global brands. Advertising effectiveness was measured in two ways: communication effectiveness (that is, perceived and actual comprehension of the advertising message and attitude towards the use of English in the commercial) and marketing effectiveness (attitude towards the commercial, the product and purchase intention). In addition, we took into account the verbal complexity of the commercials. We ran the experiment in two Belgian teenagers’ samples: a Dutch‐speaking sample (subtitling region) and a French‐speaking sample (dubbing region). We found that subtitles positively influence the communication effectiveness of English‐only commercials containing words that transcend the language level of elementary English learners. Subtitles also boost the marketing effectiveness of commercials with a significant number of words and expressions at (upper) intermediate learner's level.