It is known that South Australia (SA) has the highest rate of knee arthroscopy use of any state in Australia; however, Level 1 evidence demonstrates that knee arthroscopy in patients with uncomplicated knee osteoarthritis confers no benefit. In SA, which patients are presenting with knee pain and what treatments are they receiving? To determine the prevalence, persistence and treatment modalities of knee pain in SA. This study analysed data from the North-West Adelaide Health Study (1999-2015), a longitudinal, population-based cohort study of people aged 18 years and over (n = 4060), initially randomly selected from the north-west region of Adelaide, SA. It incorporated clinic assessments, self-completed questionnaires and telephone interviews to collect demographic, anthropometric and biochemical data over four main stages (1, 2, 3 and North-West 15 (NW15)). Data were linked to Medical Benefits Scheme data. In stages 3 and NW15 of the North-West Adelaide Health Study, 30-35% of participants reported knee pain (n = 803, 452). Demographic variables associated with knee pain included older age and lower educational level, while risk factors included obesity and high waist circumference. In the 12 months preceding NW15, 33% of participants with knee pain/stiffness consulted a general practitioner for their knee pain, 10.2% an orthopaedic surgeon, and 12.6% a physiotherapist. Between 2011 and 2015, 3.0% the cohort underwent a knee arthroscopy, and 3.1% underwent knee magnetic resonance imaging. Knee pain affects large proportions of the SA population. Knee pain was persistent with underuse of non-pharmacological treatments and high use of specialist referral. These data support the need for a national strategy to manage osteoarthritis effectively.