Emphasizing the power and fundamental nature—comparable to the basic mammalian drive for food—of sex drives and urges in almost everybody, including paraphilics and sex offenders, this article gives an overview of biologically-based, or “organic” approaches to the treatment of paraphilics and sex offenders. Organic treatment approaches for this population may be divided into surgical and pharmacotherapeutic categories. Surgical approaches include castration (orchiectomy), sterotactic (brain) surgery and estrogen implants, the latter two approaches are not used in the United States (U.S.). All surgical approaches act hormonally, in reducing or blocking the amount of circulating androgens in the subject. Pharmacotherapeutic approaches include: (1) Indirect-acting and direct-acting antiandrogen hormones, also intended to reduce or block the amount of circulating androgens in the subject. (2) Psychotropic medications for primary treatment of male aggressive hypersexuality, for treatment of co-occurring psychiatric symptomatology, or for both. (3) An experimental pharmacologic approach to the treatment of this population consists of the use of antiepileptic drugs, or “AED's” to stabilize the impulsivity/compulsivity of these subjects, in reducing the hypothesized “kindling” that may occur during impulsive/compulsive periods in these individuals. Whatever organic approach may be used for paraphilics and sex offenders, such an approach alone is not sufficient treatment for this population. Psychotherapeutic and cognitive/behavioral approaches must also be included in these individuals' treatment regimens. A companion piece to this article, giving an overview of psychotherapeutic and cognitive/behavioral treatment approaches to this population will be published in a future issue of this Journal.