Courtship signals are expected to be consistent within but vary between males of different qualities. Such traits are, therefore, predicted to exhibit high repeatability. However, studies have shown that courtship behaviors vary greatly in their within-individual repeatability, resulting in substantial variation in their ability to reflect male quality. This has implications for the evolution of female mate choice and courtship communication, as low levels of repeatability may reflect courtship signals that do not provide accurate quality information to females. In this article, we tested whether male courtship shuddering in the tropical orb-web spider, Argiope radon, influences female mate choice. We also tested whether male shudder performance reflects male phenotypic condition and is repeatable. We found that male shudder performance and condition predicted female latency to move onto the mating thread, a measure of mate preference. Aspects of male shudder performance were positively correlated with male body condition. Further, we found surprisingly high levels of repeatability in male courtship shuddering, ranking among the highest levels recorded to date for courtship behavior. We suggest that male courtship shuddering functions as an important indicator of male quality, with strong potential to respond to selection.