Tilt in poker implies a deviation from an individual’s usual playing style, at a strategic, emotional and behavioural level. It is a specific characteristic of poker, which can affect all kinds of players with varying degrees of frequency. In addition, tilt could be a transitional form of pathological gambling behaviour and a gateway to addiction. The main objective of this research is therefore the design and validation of a measuring scale for tilt episode frequency in an online poker gamblers’ group. Twenty-one items based on the literature and interviews with 10 poker players were created. An online self-administered questionnaire was completed by 263 poker players to validate this scale. The mean age of the sample was 26.7 (SD = 4.45). The Online Poker Tilt Scale (OPTS) consists of 17 items and is the first validated tool for measuring the frequency of tilt episodes associated with online poker. It is composed of two factors: ‘emotional and behavioural tilt’ and ‘cognitive tilt’. Tilt seems to be an essential part of understanding online poker behaviour. This tool will enable researchers studying online poker addiction to perform research on the mechanisms and processes that lead to tilt and its consequences.