There is a consensus in the addictions literature that exposure to addiction-relevant cues can precipitate a desire to engage, or actual engagement, in the addictive behaviour. Previous work has shown that exposure to gambling-relevant cues activates gamblers’ positive gambling outcome expectancies (i.e. their beliefs about the positive results of gambling). The current study examined the effects of a new, arguably more ecologically valid cue manipulation (i.e. exposure to a gambling lab environment vs. sterile lab environment) on 61 regular gamblers’ explicit and implicit gambling outcome expectancies. The authors first tested the internal consistency of their implicit reaction time measure of gambling outcome expectancies, the Affective Priming Task. Split-half reliabilities were satisfactory to high (.72 to .88), highlighting an advantage of this task over other characteristically unreliable implicit cognitive measures. Unexpectedly, no predicted between-lab condition differences emerged on most measures of interest, suggesting that peripheral environmental cues that are not the focus of deliberate attentional allocation may not activate positive outcome expectancies. However, there was some evidence that implicit negative gambling outcome expectancies were activated in the gambling lab environment. This latter finding holds clinical relevance as it suggests that presenting peripheral gambling-related cues while treating problem gamblers may facilitate processing of the negative consequences of gambling.