Seborrheic dermatitis (SD) is normally treated with topical corticosteroids and antifungals. Oral therapies can be prescribed in severe or unresponsive cases. This review aims to assess the quantity and quality of published reports on oral therapies for SD. MEDLINE and Embase databases and the reference listings of publications were searched for any publication using oral treatment for SD. The quality of the included publications was assessed using a modified 27 item checklist by Downs and Black. Twenty-one publications (randomized controlled trials, open trials and case reports) covering eight oral therapies (itraconazole, terbinafine, fluconazole, ketoconazole, pramiconazole, prednisone, isotretinoin and homeopathic mineral therapy) were identified. Most of the publications investigated oral antifungals and the quality of the evidence was generally low. The clinical efficacy outcome reported varied considerably between the studies, preventing statistical analysis and direct comparison between treatments. However, ketoconazole therapy was associated with more relapses compared with other treatments. Itraconazole dosing regimen for SD was generally 200 mg/day for the first week of the month followed by 200 mg/day for the first 2 days for 2–11 months. Terbinafine was prescribed at 250 mg/day either as a continuous (4–6 weeks) or as an intermittent regimen (12 days per month) for 3 months. Fluconazole has administered daily (50 mg/day for 2 weeks) or weekly (200–300 mg) for 2–4 weeks. Ketoconazole dosing regimen was 200 mg daily for 4 weeks. Finally, a single 200 mg dose of pramiconazole was administered to patients. This review also highlights key areas for consideration when designing future studies.