Studies evaluating attentional biases in health anxiety have produced equivocal results. Little is known about the details and potential moderators of prioritized processing of illness related information. We compared individuals with health anxiety (HAG; N = 54) to not health anxious participants (CG; N = 53) in a blocked emotional Stroop paradigm. Analyses focused on differences between categories of health threatening information (words referring to symptoms and illnesses), on the time course of the emotional intrusion effect, and on test order effects. When symptom words were presented first in the experiment (i.e., before the illness words), the HAG showed a stronger emotional intrusion effect to symptom words in the first test half (trials 1–20) compared to the CG. A similar pattern of results with a smaller effect size was apparent for the illness words, when they were presented first in the experiment. The results contribute to a more fine-grained understanding of attentional processes towards external sources of threat in health anxiety. In particular, they emphasize the importance of taking into account the time course when analyzing data from an emotional Stroop paradigm.