Cue reactivity, while increasingly recognized as a central feature of drug and alcohol addiction, is not well studied in gambling. We evaluated the urge to gamble in a simulated casino environment among frequent gamblers who alternated between cycles in which they observed others playing ten hands of Blackjack (first, third and fifth cycle) and cycles in which they played ten hands of Blackjack themselves (second and fourth cycle). The played cycles served as a manipulation for the observed cycles in terms of "priming" (having previously gambled in the environment vs. not) and "anticipation" (expecting more opportunities to gamble in the environment vs. not) and, thus, allowed these conditions: observed cycle 1 = anticipation (+) and prime (-); observed cycle 2 = anticipation (+) and prime (+); and observed cycle 3 = anticipation (-) and prime (+). Subjects' urge to gamble was greater in the gambling environment than in a neutral setting and both positive anticipation and positive priming increased cue reactivity within the gambling environment. The frequency of gambling outside of the study did not affect cue reactivity. However, a preference for Blackjack (vs. other types of gambling) and observing winning (vs. losing) hands were both associated with stronger cue reactivity in the study. These findings contribute to our understanding of pathological gambling.