Introduction Medical students often lack training in advanced communication skills encompassing emotionally fraught situations and those in which an intense emotional response is expected. Such skills are required for clinical situations encountered during residency. We created and evaluated an advanced communication skills workshop (ACSW) using standardized patients for senior medical students. The workshop emphasized communication skills for four scenarios—strong emotion, goals of care, medical error, and palliative care assessment—and utilized formative peer assessment and feedback. Methods We created the four ACSW cases with case-specific communication behavior checklists and a common modified Master Interview Rating Scale in a Capstone Course for senior medical students. In groups of three, students rotated through three of four stations. Each student conducted one of the interviews while the other two completed the checklists and provided verbal feedback. We performed one-way analyses of variance on Likert responses and content analysis on open responses on a post-ACSW survey. Results Ninety-one students completed the ACSW and survey. Students assigned high value to all four ACSW student roles: interviewer, observer, feedback recipient, and feedback provider. Students rated the experience above average to excellent on nearly all survey items. Open-response themes included “liked the opportunity to give or receive peer feedback” (46%) and “found the checklists helpful” (45%). Discussion Feasible and well received by senior medical students, our ACSW offers an opportunity to practice and observe advanced communication skills and peer feedback. A peer-assisted, formative learning model, the ACSW efficiently addresses a key aspect of residency preparation.