Persons scoring high on negative affectivity (NA) have more subjective health complaints. In this study, we tested the hypothesis that high NA persons are more likely to experience internal sensations as threatening signs of health problems. Low and high NA participants (N = 44) were given four breathing trials: one room air trial followed by three trials containing 5.5% CO2 which induced transient low intensity somatic sensations. Prior to each CO2 trial, participants received either positive, negative or uncertain labelings of the sensations that might occur. Participants rated the (un)pleasantness of the experienced somatic sensations and the perceived intensity. Also respiratory responses were measured. During CO2 trials, reliable main effects of information were found but no effects involving NA were observed, neither on pleasantness ratings nor on respiratory responses. However, during room air breathing, high NA participants reported more intense somatic sensations than low NA participants. Post-experimental data suggested that high NA participants had more negative meanings and worries about the consequences of the physical sensations. It is concluded that interpretational biases in high NA is situated at the level of attributional processes.