Background: Testicular pain encompasses a vast medical diagnostic field, with numerous organ and system convergence. Acute testicular pain is a medical emergency that requires accurate evaluation and immediate resolution, whereas chronic testicular pain is enigmatic and requires sound knowledge of the mechanisms of testicular pain and the differential diagnosis.
 Objective: To review the causes of testicular pain and propose a new etiologic classification consisting of 10 subgroups. 
 Methods: A bibliographic search was carried out utilizing Google and the National Library of Medicine’s PubMed databases to identify original articles and review articles (hard copy or electronic) published on testicular pain, up to March 2020. The search included: MeSH terms: testicular disease (classification, complications, etiology, trauma, microbiology, pathology, pathophysiology, secondary, surgery, treatment) and vasectomy; Non-MeSH terms: acute and chronic orchialgia, scrotalgia, orchidynia, groin pain, epididymalgia, testalgia, chronic testicular pain, chronic scrotal pain syndrome, testicular pain syndrome, epididymal pain syndrome, and post-vasectomy pain syndrome. The initial search produced 625 articles, of which 143 were included in the present review.
 Results: To better understand testicular pain etiology, 100 possible diagnoses were divided into ten subgroups: infectious, neoplastic, traumatic, torsional, vascular, immunologic, neurologic, pharmacologic, obstructive, and miscellaneous causes. Likewise, treatment can be divided into two main groups, according to therapeutic options: pharmacologic and non-pharmacologic, with the latter subdivided into: noninvasive and the increasingly performed invasive (surgical) alternatives.
 Conclusions: Testicular pain should be understood as a complex pain syndrome of enigmatic origin. Treatment success depends on the correct identification, from hundreds of possibilities, of the cause of pain. Logical grouping of those possibilities could aid in making the accurate etiologic identification.