Objectives: Patient ‘no-shows’ (failure to keep or cancel appointments) is a global problem that impacts healthcare systems by delaying patient access to healthcare, reducing quality of care, and wasting resources. The no-show phenomenon has not yet been studied in Oman despite it having grown in importance ever since the appointments system was implemented in 2014. This study aimed to characterize the no-shows in primary healthcare facilities in Oman. Methods: We collected and analyzed administrative data during the period 2014–2017 from 14 primary healthcare institutions in Oman focusing on the ophthalmology, ear, nose, and throat, and dermatology clinics therein. Results: The overall no-show rates were > 50.0%. No-show probabilities were higher in males, younger adults, new appointments, early morning appointments, appointments during Ramadan, and appointments scheduled farther in advance. Patient experience with the appointment system reduced the no-show probability. Conclusions: Policymakers should consider these trends to optimize the number of appointments per day, and researchers should further investigate no-shows for other specialties and levels of care.