A varicocele is an abnormal dilatation and tortuosity of the veins of the spermatic cord. Although varicoceles are common in the general population and are frequently found on routine physical examinations, they represent the most common correctable cause of male factor infertility. Varicoceles are also often incidental findings on imaging studies, particularly scrotal ultrasound. Importantly, not all varicoceles should be treated equally (or at all), and basic guidelines on the evaluation and indications for treatment of adult varicoceles should be reviewed before counseling and treatment. A semen analysis should be obtained for any male patient of reproductive age considering intervention. The adolescent varicocele is managed much differently than the adult varicocele and remains a source of controversy. This review describes the clinical presentation and the evaluation of adult and pediatric varicoceles, and provides guidance on their diagnosis and workup. It also describes options for surgical repair and the success and complication rates associated with each surgical approach, ultimately supporting microsurgical subinguinal varicocele repair as the current surgical standard.