Veterans with posttraumatic stress disorder (PTSD) often exhibit an attentional bias towards trauma-relevant or generally threatening and negative stimuli. Internet-based cognitive behavioral therapy (ICBT) has been demonstrated to be efficacious in the treatment of PTSD. However, a previous study by our own group failed to find a symptom reduction following ICBT in a sample of traumatized veterans. No previous studies have examined the usefulness of ICBT in terms of modifying attentional bias in PTSD. In an eye-tracking experiment, veterans with deployment-related PTSD were presented with combat-related pictures and general threat-related pictures. These target stimuli were simultaneously displayed with neutral pictures. Additionally, participants were presented with pairs of emotional and neutral faces. Participants received ICBT, and attentional bias was examined pre- and post-intervention and at three-month follow-up. No significant changes in attentional bias were observed, either from pre- to post-intervention or at follow-up. The findings suggest that attentional bias reduction is associated with, rather than being separable from, overall PTSD symptom improvement. The present eye-tracking study was the first longitudinal investigation to examine the effect of ICBT on PTSD-related attentional bias in a sample of veterans. More research is needed to gain a deeper understanding of the underlying mechanisms of attentional bias in PTSD and its modifiability.