Objectives: To examine the validity of clinical tests available for the diagnosis of longstanding groin pain in athletes. Design: Systematic review. Method: A published search strategy of MeSH terms in MEDLINE, CINAHL, EMBASE, and SportDiscuss. Inclusion criteria: diagnostic studies relating to athletic groin pain, professional or semi-professional athletes, symptoms lasting for more than six weeks, and not limited by age or gender. A priori exclusion criteria were utilised. Outcome measures: QUADAS tool, sensitivity and specificity, likelihood ratios and predictive values of the reported tests and investigations. Results: 577 Journal articles were identified. Five studies met all requirements. Sensitivity and specificity of clinical tests ranged between 30 and 100% and 88 and 95% respectively with negative likelihood ratio of 0.15–0.78 and positive likelihood ratios of 1.0–11.0. Sensitivity and specificity of investigations (MRI, herniography, and dynamic ultrasound) ranged between 68% and 100% as well as 33% and 100% respectively with negative likelihood ratios between 0 and 0.32 and positive likelihood ratios between 1.5 and 8.1. Conclusion: There is a lack of validated diagnostic clinical tests available for clinicians and a lack of symptomology being evaluated. It is recommended that a reference standard should be applied and data should be reported in sufficient detail to calculate diagnostic statistics that is useful to the clinician.