Varicocele is a common disease in men, with a global incidence of approximately 25%. A comprehensive and systematic analysis of the knowledge map on it will help in assessing frontier research and identify knowledge gaps. In total, 4103 articles published from 2002 to 2021 in 1066 journals were included. They represent the current research status worldwide, potential hotspots and future research directions. In the past decades, the number of publications and citations of varicocele-related studies have increased steadily. Academic institutions in the United States played a leading role in varicocele research. The country, institution, journal and author with the most publications were the United States (779), Cleveland Clinic Foundation (132), Andrologia (246) and Agarwal A (106), respectively. The most frequently used keywords were Varicocele (1620), Male Infertility (944), Varicocelectomy (288), Testis (245), Sperm (166), Oxidative Stress (144), Azoospermia (119), Semen Analysis (118), Laparoscopy (116) and Adolescent (97). Currently, the main focus of current varicocele research is its surgical treatment method and effect on sperm quality. The frontier research hotspot is the specific mechanism of varicocele-induced decrease in sperm quality.