Objectives: To improve benign prostatic hyperplasia (BPH) care, the American Urological Association created the best practice guidelines for BPH management. We evaluated the trends in use of BPH-related evaluative tests and the extent to which urologists comply with the guidelines for these evaluative tests. Methods: From a 5% random sample of Medicare claims from 1999 to 2007, we created a cohort of 10 248 patients with new visits for BPH to 748 urologists. The trends in use of BPH-related testing were determined. After classifying urologists by compliance with the best practice guidelines, the models were fit to determine the differences in the use of BPH-related testing among urologists. Additional models were used to define the extent to which individual BPH-related tests influenced guideline compliance. Results: The use of most BPH testing increased with time (P <.001) except for prostate-specific antigen (declined; P <.001) and ultrasonography (P =.416). Northeastern and Midwestern urologists were more likely to be in the lowest compliance group compared with Southern and Western urologists (29%, 27%, 13%, and 19%, respectively; P =.01). The testing associated with high guideline compliance included urinalysis and prostate-specific antigen measurement (P <.01 for both). Prostate ultrasonography (P =.03), cystoscopy (P <.01), uroflow (P <.01), and postvoid residual urine volume determination (P =.02) were associated with low guideline compliance. Urodynamics, postvoid residual urine volume, cytology, serum creatinine, and upper tract imaging were not strongly associated with guideline compliance. Conclusions: Despite the American Urological Association guidelines for BPH care, wide variations in the evaluation and treatment were seen. Improving guideline adherence and reducing variation could improve BPH care quality.