Objective: To review the epidemiological differences between culture‐positive and culture‐negative (but ipaH PCR‐positive) cases of shigellosis in Sydney Local Health District (SLHD), NSW, to inform whether changes to the national case definition for shigellosis are required. Methods: An audit of all cases of shigellosis (culture‐positive vs. culture‐negative/PCR‐positive) in SLHD from 1 January 2013 to 30 June 2015 was conducted and demographic, clinical and risk factors were analysed and compared between these groups. Results: Of the 148 shigellosis cases notified to SLHD, 122 cases (85 culture‐positive vs. 37 culture‐negative) were included for analysis. Culture‐positive cases were more likely than culture‐negative/PCR‐positive cases to have experienced at least three symptoms (OR 3.18, 95%CI 1.3–7.5), been hospitalised (OR 4.2, 95%CI 1.4–13.2), and have had men‐who‐have‐sex‐with‐men exposure identified as the source of their infection (OR 28.7, 95%CI 6.2–132.6). Conclusions: This study has identified that culture‐positive vs. culture‐negative/PCR‐positive shigellosis cases in NSW differ by clinical severity and risk factors for infection. Implications for public health: The study findings warrant further research to determine the true diagnostic prevalence of Shigella in the culture‐negative/PCR‐positive group in the Australian context, in order to inform further changes to the national case definition for shigellosis.