In many countries where gambling is legalised, there has been a strong public policy focus on the need for strategies to reduce gambling related harm. These have often included policies requiring staff in gambling venues to identify and/or assist people who might be experiencing gambling-related harm. To facilitate this process, researchers have developed visible behavioural indicators that might be used to profile potentially problematic gambling. Few of these studies have, however, examined whether such indicators or 'warning signs' might differ between men and women. In this study, we describe the results of an analysis of data drawn from 1185 fortnightly gamblers that included 338 problem gamblers as classified by the Problem Gambling Severity Index. Indicators of problem gambling were similar between males and females with a few key exceptions. Indicators reflecting emotional distress were more commonly reported by females with gambling problems, whereas problem gambling males were more likely to display aggressive behaviour towards gambling devices and others in the venue. Amongst males, signs of emotional distress as well as attempts to conceal their presence in venues from others most strongly differentiated between problem and non-problem gamblers. Amongst females, signs of anger, a decline in grooming and those attempts to access credit were the most distinguishing indicators. These findings have implications for the refinement of identification policies and practices.