Individuals vary widely in their ability to translate complex spatial information into performing physical tasks. Much of the variability can be explained by their experience in using different information formats and differences in individual spatial cognition. Traditional delivery of mechanical, electrical, and plumbing (MEP) designs rely on two-dimensional isometric drawings. Advancements in three-dimensional (3D) computer-aided design (CAD), augmented reality, virtual reality, and 3D printing have provided new format options for delivering engineering information; however, providing them to crafts for use at the construction workface remains relatively rare. The objective of this research is to understand how eye-gaze patterns of construction craft workers is influenced by information formats and spatial cognition when building a complex spatial task. A series of field trials with MEP workers was conducted to examine the influence of information format and spatial cognition on their eye-gaze patterns in building a scale-model pipe assembly. Participants were provided eye-tracking glasses along with one of three information formats: two-dimensional (2D) isometric drawings, 2D isometric drawings supplemented with a 3D image of the assembly, and 2D isometric drawings supplemented with a 3D physical model of the assembly. Card rotation and cube comparison tests were administered to measure spatial cognition. The results of this paper reveal that the information format and spatial cognition significantly influenced workers’ eye-gaze patterns; there are different gaze patterns for different information formats, and these differences in gaze patterns were associated with differences in spatial cognition abilities. Additionally, the improvement in performance when using different engineering information formats is associated with different eye-gaze patterns.