This cross-sectional study was performed to determine the consumption rate, duration, and methods of herb or vitamin/mineral use by patients with cancer and to evaluate the effects of alternative therapies in Kayseri, Turkey. A face-to-face interviews was conducted with 203 patients. Results showed that 32% and 18.2% of the patients used herbs or vitamin/mineral supplements, respectively. Nettle was the most commonly used herb, and iron and vitamin C were the most commonly used supplements. There was a significant difference between herb or vitamin/mineral users and nonusers with regard to educational levels. In conclusion, patients with cancer highly tended to use herb or vitamin/mineral supplements.