It has been suggested that affect may play an important role in risk perception. Slovic et al. argued that people make use of the “affect heuristic” when assessing risks because it is easier and more efficient to rely on spontaneous affective reactions than to analyze all available information. In the present studies, a single category implicit association test (SC-IAT) to measure associations evoked by different hazards was employed. In the first study, we tested the extent to which the SC-IAT corresponds to the theoretical construct of affect in a risk framework. Specifically, we found that the SC-IAT correlates with other explicit measures that claim to measure affect, as well as with a measure of trust, but not with a measure that captures a different construct (subjective knowledge). In the second study, we addressed the question of whether hazards that vary along the dread dimension of the psychometric paradigm also differ in the affect they evoke. The results of the SC-IAT indicated that a high-dread hazard (nuclear power) elicits negative associations. Moreover, the high-dread hazard evoked more negative associations than a medium-dread hazard (hydroelectric power). In contrast, a nondread hazard (home appliances) led to positive associations. The results of our study highlight the importance of affect in shaping attitudes and opinions toward risks. The results further suggest that implicit measures may provide valuable insight into people's risk perception above and beyond explicit measures.