Biometrics technology is one of the most important and effective solutions for personal authentication. In recent years, as one of the emerging biometrics technologies, dorsal hand vein (DHV) biometrics has received a lot of attention. In fact, DHV biometrics has been studied for more than 30 years, during which different problems related to DHV recognition have been addressed. In this paper, we conduct a comprehensive survey on the state-of-the-art in DHV biometrics. Nearly all important aspects of DHV biometrics have been summarized, including the developmental history, data acquisition, databases, preprocessing algorithms, feature extraction and matching algorithms, information fusion schemes and commercial products. We also discuss the challenges and future directions in DHV biometrics research.