This article reviews the current concepts, recommendations, and principles of fertility preservation in men with cancer. Obstacles to sperm banking are addressed, as well as future directions for fertility-preserving technologies. All cancer therapies--chemotherapy, radiation, and surgery--are potential threats to a man's reproductive potential. Additionally, cancer itself can impair spermatogenesis. Thus, sperm cryopreservation prior to initiating life-saving cancer treatment offers men and their families the best chances to father biologically-related children and should be offered to all men with cancer before treatment. Better patient and provider education, as well as deliberate, coordinated strategies at comprehensive cancer care centers, are necessary to make fertility preservation for male cancer patients a priority during pre-treatment planning.