The relationship between differences in individuals' past experience viewing stereoscopic images and their discomfort associated with 3D video was examined. In the current study, 21 subjects were categorized as either inexperienced or experienced viewers of stereoscopic images (12 and 9 subjects, respectively). Two commercially available 3D movies with different depth and motion characteristics were presented to the subjects under two different viewing conditions. Eye discomfort, fatigue in parts of the body, and mental workload were measured. We found that experienced viewers were affected more from moderate depth video with less motion, perhaps because of their higher degree of attention toward subtler depth detail. Experienced viewers reported more severe fatigue in the upper parts of their bodies, which could be attributed to their body adjustments effected in an effort to optimally receive depth information. Inexperienced viewers were affected more by images with more depth and motion, a result perhaps of their initial excitement to experience the new technology. It was shown that particularly depth-emphasized segments demand higher mental workload from experienced viewers, but the effect is transient and not cumulative. It was found that differences between the two groups are exaggerated under the near viewing condition.