AIM: The aim of the present study was to investigate the diagnosis, treatment, and referral patterns of periodontal patients by general dental practitioners (GDP). METHODS: A questionnaire was mailed to registered GDP with publicly-listed postal addresses in Tasmania, Australia. Information was collected on demographics, training and professional development, examination, diagnosis and referral patterns, and periodontal treatment patterns. RESULTS: Seventy-seven (44.5%) questionnaires were completed. Over 85% always or usually screened for periodontal disease. On average, 0 to ≤7 patients were diagnosed with periodontal disease. GDP were always or usually confident in treating gingivitis (100%), mild (98.7%) and moderate periodontitis (73.7%), and rarely or never confident in treating severe (81.6%) and aggressive periodontitis (86.8%). Over 38% frequently referred to periodontists, 35.5% sometimes, 21.1% rarely, and 5.3% never. Clinical factors associated with referral were periodontal pocketing of ≥6 mm, tooth mobility, no improvement following treatment, and a complex medical history. CONCLUSIONS: Most GDP performed periodontal screening and diagnosis. They were confident in treating gingivitis and mild-to-moderate periodontitis. Referral to a periodontist was associated with disease severity, tooth mobility, a complex medical history, or unsuccessful treatment.