The National Institute for Occupational Safety and Health (NIOSH), in cooperation with the Canadian Forces Health Services Group Headquarters, U.S. Army Tank-Automotive and Armaments Command (TACOM), and the Ministry of Health & Long-Term Care, Ontario (Canada), conducted a test program to evaluate the capability of mobile restraint systems to protect occupants in the patient compartment of an ambulance. This paper focuses on the vehicle chassis behavior and acceleration pulses as seen in each test conducted to support the program. This program consisted of testing one Type I ambulance mounted on a Ford F-350 truck chassis (1994 vintage), and three Type III ambulances mounted on Ford E-350 van chassis (two 1993, and one 1999 vintage). A vehicle-to-vehicle side impact test was conducted using the Type I ambulance with a targeted change in velocity of 27.4 kph (17 mph). A 1984 Chevrolet Sierra 2500 was the impacting vehicle for the side test. Fixed barrier frontal tests were conducted using the Type III ambulances with a targeted impact velocity of 48 kph (30 mph). In addition to an x-axis, or forward component, each of the frontal crash pulses was found to have a significant z-axis, or vertical, component which caused a forward rotation of the patient compartment ranging up to approximately 16.5 degrees. Significant cab-intrusion was observed as a result of the frontal tests that were conducted. Vehicle weights ranged up to 5005 kg (11,035 lbs.) and were similar to operational weight conditions. The paper includes a detailed description of the crash test setup as it pertains to the chassis, vehicles tested, instrumentation, limited crush measurements, testing observations, and the resulting multi-axial pulses measured at multiple frame and patient compartment locations. This data will be of interest to ambulance and other multi-stage vehicle manufacturers for use in design, modeling, and sled testing.