In a report, the Care Quality Commission (CQC) said there were "significant areas of concern" at the Widbrook Medical Centre in Trowbridge.
Inspectors found issues with systems and processes, but said the level of care given to patients was "good".
The medical centre has pledged to improve services.
The health regulator inspected the practice in December and was told the booking and telephone systems made it difficult for patients to get an appointment that was suitable for them.
Inspectors found staff were good at raising concerns and reporting incidents but there was no formal structure for "sharing any learning within the practice".
Sufficient recruitment checks to verify that staff are "of good character and have the qualifications and competence" to carry out their jobs was also criticised.
However, inspectors said the majority of patients "were treated with compassion, dignity and respect".
A spokesman for the medical centre said an action plan to address the findings of the inspection was being put in place.
He said: "We will continue to improve the service we provide to our patients so that our patients are confident they are receiving a quality general practice service and are reviewing our appointment system to support our patients."
A GP practice in Wiltshire has been placed in special measures after its overall quality of services was rated "inadequate".