We sought to develop a reliable and valid measure of patient self-efficacy within the context of productive communication and positive attitude for cancer patients. A set of 19 potential items for the Communication and Attitudinal Self-Efficacy scale for cancer (CASE-cancer) was pilot tested with 50 cancer patients. Based on the pilot test, item valence was made consistent (i.e., all items worded positively) and the response scale was simplified. The CASE-cancer was then administered to 127 persons receiving cancer treatment at general oncology clinics in Shreveport, Louisiana and Chicago, Illinois. Psychometric analyses revealed three 4-item factors: understanding and participating in care, maintaining a positive attitude, and seeking and obtaining information. The CASE-cancer proved to have high internal consistency and construct validity. Moreover, scale items performed similarly across literacy levels. The CASE-cancer is a psychometrically-sound tool that may provide new information on important mediating factors of cancer care. Our two-step approach to presenting response options may also provide a model for helping lower literate patients more accurately respond to survey items.