The diagnostic workup of male infertility should include a detailed history, physical examination, and semen analysis, followed by imaging. Ultrasound is the most used and critical imaging modality as a first step in evaluating young men. Male infertility is related mainly to three causes: sperm production, sperm function, or seminal pathways blockage (complete or partial) that prevent the delivery of sperm. Each factor may be isolated or associated. Scrotal ultrasound is devoted to evaluating testicular failure and proximal obstruction, while transrectal ultrasound evaluates the prostate gland, deferens, seminal vesicles, and ejaculatory ducts. Obstructions are classified as proximal and distal. Proximal obstructions involve the intratesticular seminal pathways, epididymis, and pre-inguinal deferent duct. Distal obstructions involve the distal deferent duct and the ampullo-vesicular-ductal tract. Complete bilateral obstructions of the seminal pathways result in azoospermia, while monolateral complete or bilateral incomplete obstructions are often associated with oligo-astheno-terato-zoospermia and are more difficult to recognize. Ultrasound (US) remains the mainstay imaging modality as it is non-invasive, widely available, and is able to rule out many of the abnormalities relevant to male infertility. MRI is useful in problem-solving. Invasive techniques such as seminal vesicle aspiration cytology and vasography are generally reserved before therapeutic intervention in selected cases.