Enhancement of the photodegradation of bisphenol A (BPA) by beta-cyclodextrin (beta-CD) was investigated under a 30 W UV disinfection lamp (lambda(max) = 254 nm). The photodegradation rate of BPA in aqueous solutions with beta-CD was faster than that in aqueous solutions without beta-CD; for example, after 50 min of UV irradiation, beta-CD had increased the photodegradation efficiency by about 46.5% for 10 mg dm(-3) BPA. The photodegradation of 2.5-20 mg dm(-3) BPA in aqueous solutions was found to follow pseudo-first-order kinetics. The first-order rate constant showed a 12-fold increase in the presence of beta-CD. Factors such as beta-CD concentration, pH, BPA initial concentration and organic solvent influencing the photodegradation of BPA were studied and are described in detail. Variations in the pH and electrical conductivity of solutions were observed during the photodegradation process. The enhancement of photodegradation of BPA results mainly from the lower bond energy between some atoms in the BPA molecule after inclusion interaction with beta-CD. (c) 2006 Society of Chemical Industry.