Listening is regarded as a key requirement for successful communication and is fundamentally linked to other language skills. Unlike reading, it requires both hearing and processing information in real-time. We therefore propose that the ability to concentrate is a strong predictor of listening comprehension. Using structural equation modeling, concentration was found to be a strong predictor of listening comprehension in a sample of 345 sixth graders in Switzerland. In contrast, the ability to concentrate did not predict successful reading comprehension. The most important predictor of both listening and reading comprehension was vocabulary.