This study will be conducted as a prospective, single-center (multiple clinics), single-arm open phase IV study.

the study will follow hypogonadal patients, and aimed to confirm the hypothesis that testosterone undecanoate improves the patient satisfaction and quality of life, with parallel improvement in their spouses's quality of life and satisfaction. Each patient/spouse will serve as his own control.

the study protocol will follow hypogonadal patients, who initiate treatment with testosterone undecanoate, given in accordance with the standard protocol.

Hypogonadal men eligible for treatment with testosterone undecanoate, who have not been treated with testosterone undecanoate within the last 6 months prior to enrollment, can be enrolled in the study. Patients who were treated with another testosterone formulation (eg. testosterone gel, testosterone enanthate injections) will require a 4 week wash-out period. Patients must be enrolled after the decision for treatment with testosterone undecanoate has been made.

Patients will be followed for an observation period of 28 weeks. Observations will be recorded at 3 consecutive visits, and will assess patient and spouse satisfaction and quality of life with validated questionnaires.

The study design is an intra-individual comparison. Each patient/spouse serves as his own control.

a laboratory test for total testosterone level will be required in the last visit. the need for concomitant phosphodiesterase-5 inhibitors use will also be recorded and analyzed.

Inclusion Criteria:

• Hypogonadal patient age 40 to 80 who has newly been prescribed testosterone undecanoate.
• The patient must be in a stable (>3 months) heterosexual relationship to be eligible for the study
• Diagnosis of hypogonadism at the discretion of the physician, based on patient's symptoms and a laboratory evidence of T levels below 12 (symptomatic patients with borderline levels of 8.4 to 12 are also eligible for testosterone replacement therapy)
• Wash-out of 6 months for testosterone undecanoate, 4 weeks for other testosterone formulations, before study entry.
• Patient & spouse must be capable and willing to fill-in questionnaires to be enrolled in the study
• Informed consent is required

Exclusion Criteria:

• The standard contraindications and warnings of treatment with testosterone replacement therapy, and specifically testosterone undecanoate, must be followed. Contra-indications as copied from the product prescribing information are: androgen-dependent carcinoma of the prostate or of the male mammary gland; past or present liver tumors; hypersensitivity to the active substance or to any of the excipients
• Men with desired paternity will be excluded

community based population of hypogonadal men, who are eligible and choose the treatment with testosterone undecanoate