Background Medical records play a fundamental role in healthcare delivery, quality assessment and improvement. However, there is little objective evidence on the quality of medical records in low and middle- income countries. Objective To provide an unbiased assessment of the quality of medical records for outpatient visits to rural facilities in China. Methods A sample of 207 township health facilities across three provinces of China were enrolled. Unannounced standardised patients (SPs) presented to providers following standardised scripts. Three weeks later, investigators returned to collect medical records from each facility. Audio recordings of clinical interactions were then used to evaluate completeness and accuracy of available medical records. Results Medical records were located for 210 out of 620 SP visits (33.8%). Of those located, more than 80% contained basic patient information and drug treatment when mentioned in visits, but only 57.6% recorded diagnoses. The most incompletely recorded category of information was patient symptoms (74.3% unrecorded), followed by non-drug treatments (65.2% unrecorded). Most of the recorded information was accurate, but accuracy fell below 80% for some items. The keeping of any medical records was positively correlated with the provider’s income ($β$ 0.05, 95% CI 0.01 to 0.09). Providers at hospitals with prescription review were less likely to record completely ($β$ -0.87, 95% CI -1.68 to 0.06). Significant variation by disease type was also found in keeping of any medical record and completeness. Conclusion Despite the importance of medical records for health system functioning, many rural facilities have yet to implement systems for maintaining patient records, and records are often incomplete when they exist. Prescription review tied to performance evaluation should be implemented with caution as it may create disincentives for record keeping. Interventions to improve record keeping and management are needed.