The prevalence of androgen deficiency in men increases with aging. Two common instruments, the Aging Male Symptoms (AMS) scale and the Androgen Deficiency in the Aging Male (ADAM) questionnaire, are often used to screen for androgen deficiency in clinical practice. The aim of this study is to compare the capability of the AMS scale and the ADAM questionnaire to detect androgen deficiency in middle-aged Taiwanese men. In April 2008, a free health screening was conducted by Kaohsiung Medical University Hospital. All participants completed a health questionnaire and had blood samples drawn between 8:00 am and noon. Serum total testosterone (TT), albumin, and sex hormone-binding globulin levels were measured. The level of free testosterone (FT) was calculated. Clinical symptoms associated with androgen deficiency were screened by using the AMS scale and ADAM questionnaire. Androgen deficiency was defined as TT < 300 ng/dL or both TT < 300 ng/dL and FT< 5 ng/dL. In total, 339 men were included in the final analysis, with the mean age of 54.6 ± 4.9 years (range, 47-65 years). Androgen deficiency was found in 75 men (22.1%) based on the criteria of TT < 300 ng/dL, and in 54 men (15.9%) based on the criteria of TT < 300 ng/dL and FT < 5 ng/dL. When detecting participants with both TT < 300 ng/dL and FT < 5 ng/dL, the sensitivity and specificity of the AMS scale were 57.4% and 48.1%, compared with 66.7% and 25.6% for the ADAM questionnaire. In a sample of middle-aged Taiwanese men, neither the AMS scale nor the ADAM questionnaire had sufficient sensitivity and specificity to detect androgen deficiency. In addition to using those 2 screening instruments, a thorough physical and biochemical workup should still be conducted in patients at risk or suspected of androgen deficiency.