Missed general practice appointments have considerable time and cost implications for the NHS, and leaves patients with unmet health needs, and potentially delayed diagnoses or medical treatment. This systematic review, entitled Which patients miss appointments with general practice and the reasons why updated work conducted in 2003, and aimed to examine the rate of missed booked appointments, which patients are more likely to miss appointments, and some reasons for this. Findings of this review has potential implications for practices in targeting interventions to patients that are at increased likelihood of missing appointments, and in attempting to overcome common reasons that appointments are missed.