Currently in the United Kingdom, there is no standardised education for healthcare professionals on primary lymphoedema. Therefore the condition is often under or misdiagnosed. Early diagnosis and treatment reduces its psychological and social impact and delays disease progression and the onset of complications. A systematic review (SR) was conducted to assess the reported time between the onset of symptoms and diagnosis and the impact of a delayed diagnosis on quality of life (QoL) in patients with primary lymphoedema. Electronic databases (Medline, Embase, Cochrane) were interrogated in May 2019 to identify English-language studies reporting the time between onset of symptoms and final diagnosis in patients (all ages) with primary lymphoedema. Data reporting the impact of delay on QoL outcomes were also captured. Studies reporting syndromes with clinical presenting features unrelated to lymphoedema were excluded. The database search identified 2,869 citations of which 29 publications met the pre-defined inclusion criteria. In paediatric studies, the time from symptom onset to lymphoedema diagnosis ranged from 0-12 years (reported in 15 studies). In adults the time to diagnosis ranged from 3-50 years (14 studies) with the majority of studies (11/14 studies) reporting a delay of >14 years before an initial diagnosis was obtained. QoL data were captured qualitatively in three studies (2 paediatric and 1 adult) with all reporting that delayed diagnosis was associated with psychological stress in patients or relatives. This SR provides a comprehensive review of the current evidence base and although there is a paucity of adequately powered studies, data are suggestive of a substantial time delay between symptom onset and diagnosis which impacts negatively on QoL. Further data are required to address this evidence gap and additional education of healthcare professionals may help avoid clinical, psychological, and cost implications of a delay or misdiagnosis of primary lymphoedema.