Missed appointments place a costly and disruptive strain on National Health Service resources in England. One major source of missed appointments appears to be insufficient communication between patients and providers. SMS text messaging shows promise as a simple, cost-effective means of bridging this communications gap. SMS provides an instant and asynchronous means of communication that protects patient privacy. The potential for this technology is balanced, however, by the lack of high-quality evidence to support its use. There is an urgent need for robust evaluation of critical quality, safety, cost implications, and acceptability before the large-scale rollout of SMS-based systems.