Evaluations of the nature of an individual's sexual functioning are done with relative frequency in today's clinical healthcare environment, often prompted by sequelae of a medical disorder (e.g. diabetes, breast cancer), surgical procedure (e.g. bilateral oophorectomy), or prescribed medications (SSRI antidepressant, antihypertensive). In addition, an increasingly large number of evaluations of sexual functioning are done in association with clinical trials research in the rapidly emerging field of sexual medicine. Although clinical and research assessments of sexual functioning share many similarities, they can also be quite different, with distinct perspectives and goals regarding the assessment process. Research evaluations tend to be narrowly focused on an index condition, with highly defined patient characteristics, and long lists of inclusion/ exclusion criteria. Treatment regimens are defined by research protocol a priori, and assigned through randomization, with few options for alternatives. The process results in a rigorously defined sample of patients, but one that may be hard to generalize from to real world clinical reality. Clinical sexual evaluations, on the other hand, tend to arise in a much broader health context. There are no exclusionary patient characteristics; medical, psychological, and relationship complexities all form the context in which the patient's sexual functioning occurs, and must be factored in to the clinical evaluation and treatment recommendations. Regardless of which context gives rise to the evaluation, there are three basic sources of data that we draw from: psychometric assessment, clinical interview and laboratory assays. The clinician doing a sexual evaluation must assimilate and integrate the data from these three sources in an iterative process and arrive at a cogent diagnosis and treatment plan.