Primary cutaneous adenoid cystic carcinoma (PCACC) is a rare tumor originating within the skin, typically presenting as a solid, gradually enlarging nodule or mass. We report a unique case of recurrent PCACC of the scalp in a 90-year-old male, initially diagnosed in 2010 and managed with surgical excision. Despite initial treatment, the lesion recurred twice, necessitating re-irradiation due to ineligibility for surgical resection at the second recurrence. We discuss the treatment modalities and outcomes of this case, highlighting the importance of a multidisciplinary approach in managing rare malignancies. Our case underscores the feasibility and efficacy of radiotherapy as a palliative treatment option for recurrent PCACC, particularly in patients unsuitable for surgical intervention.