Problem Appointment adherence is essential to providing high-quality healthcare. However, missed appointments are common in the outpatient setting. Nonattendance has been shown to decrease quality of care, reduce revenue, and increase healthcare burdens. A pediatric cardiology clinic identified an 18% nonattendance rate. Purpose This quality improvement project implemented staff mediated reminder calls to reduce the nonattendance rate at an urban pediatric cardiology clinic. Methods The project team consisted of a Quality Improvement Project Lead (QI-PL), two scheduling specialists, and a nurse practitioner (NP). Scheduling specialists called patients with an appointment reminder 3-7 days prior to their appointment using a standardized script. Staff assessed and addressed barriers to attendance per clinic policy. Outcome measures were nonattendance rates and reminder call compliance. Additional data was collected for attendance barriers. Results The average nonattendance rate after implementation was 12.02%. This was a 33.22% reduction from the pre-implementation nonattendance rate of 18%. Call compliance averaged 80.55%. The most common barriers to attendance identified were directions to the clinic, language barriers, and insurance coverage. Conclusions Staff mediated reminder calls are a feasible solution to reduce nonattendance.