Nonoxynol-9 (N-9) is the most active ingredient in commercially available spermicidal products in the United States. There are many applications of cyclodextrin inclusion complexes (CD-ICs), but there are no reported studies investigating the formation of and controlled release from a N-9 spermicide-CD-IC. We have successfully formed the inclusion compound between N-9 and (alpha-CD using a solution-heating technique. The N-9-alpha-CD-IC was characterized by Fourier Transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and wide angle X-ray diffraction observations. Silicone elastomer (SILASTIC MDX4-4210) film embedded with crystalline N-9-alpha-CD-IC was prepared and evaluated for its efficacy in the controlled release of N-9 spermicide against bovine sperm. Silicone elastomer with N-9-alpha-CD-IC was as successful in reducing the motility and viability of bovine spermtazoa as silicone elastomer swollen with an equivalent amount of neat N-9. The permeability of the flexible silicone elastomer apparently enables the N-9 spermicide to diffuse from its embedded inclusion complex crystals to contact, immobilize, and kill bovine sperm cells.