Background: Between 33% and 64% of cancer patients experience pain; however, despite effective treatment options, as many as 40% of patients with pain do not receive adequate pain management. And while potential to reduce pain has been shown in several interventions that support patients' self-management of cancer pain, effects to date have been moderate. However, in a recent randomized controlled trial (RCT), Miaskowski's PRO-SELF© Pain Control Program (PCP) showed statistically and clinically significant pain reduction. This intervention was subsequently adapted for a second trial as PRO SELF© Plus PCP. The planned multi-center mixed methods study is based on this earlier work. In our previous pilot study, the PRO-SELF© Plus PCP was translated and adapted for a German speaking population. The feasibility of the intervention and study procedures was established and the intervention enhanced based on the pilot study's implications.