OBJECTIVES: Bleeding is a common experience for acute coronary syndrome (ACS) patients who receive anti-platelet medications. “Nuisance” bleeding and bruising – non-life threatening events that occur in the patients’ everyday lives and may impact medication adherence – is not often assessed in clinical trials and existing measures may not capture all relevant aspects. In this study, we used qualitative interviews to better understand how patients experience nuisance bleeding and bruising and its impact. METHODS: One-hour interviews were conducted using a semi-structured interview guide with patients who had experienced ACS in the past year. All participants were taking clopidogrel at the time of enrollment into the study and reported experiencing nuisance bleeding and bruising. Most patients were male (70%) and white (80%) and the average age was 63.5 years old. Interview responses were coded using ATLAS.ti software. Data were analyzed by extracting relevant themes emerging from the interviews and by calculating the percent of patients expressing a specific concept related to nuisance bleeding and bruising. RESULTS: Prominent features included the amount of bleeding, difficulty stopping the bleeding, and the size and color of bruises. Frequency was an important issue for patients; approximately one-third of patients reported experiencing nuisance bleeding daily. Patients most often reported that bleeding events lasted only minutes, but that bruises often did not heal for weeks. Nuisance bleeding and bruising appeared to have a significant negative impact on the patients’ daily lives, as it resulted in behavior changes to avoid bleeding and bruising events and a variety of negative emotions (e.g., embarrassment, frustration, fear). CONCLUSIONS: Nuisance bleeding and bruising can have a significant impact on the lives of ACS patients on anti-platelet medications. The data from this qualitative interview study may allow for improved measures of nuisance bleeding and bruising that can be administered in studies examining antithrombotic therapies.