A study was conducted to assess the ergonomic hazards of ironwork job tasks associated with concrete reinforcement work at a large highway construction site. PATH (posture, activity, tools, and handling) analysis, a work-sampling method, was used to provide task-based estimates of the percentage of time ironworkers spent in specified postures of the trunk, arms, and legs; performed activities; used tools; and handled loads. A total of 2128 PATH observations were made of 17 ironworkers performing 5 job tasks: (1) ground-level reinforcement bar (rebar) construction, (2) wall rebar construction, (3) ventilation rebar construction, (4) preparation work, and (5) supervising. Nonneutral trunk postures were observed frequently (exceeding 30%) and manual material handling (MMH) was the most commonly observed activity (exceeding 20%) for all job tasks except supervising. The percentage of time workers spent in specific postures, activities performed, tool use, and MMH activities differed significantly between the five main job tasks, even when supervising was excluded from the analysis. It was concluded that ironworkers are exposed to significant ergonomic hazards when performing concrete reinforcing tasks, and that opportunities exist for the implementation of ergonomic interventions. Further, the results of this study can be used to target specific hazardous tasks for ergonomic interventions and confirms the need to use a task-based exposure assessment strategy to properly assess ergonomic risk profiles for nonstructured jobs such as construction.