To improve availability of arterial line placement, we developed a nonphysician protocol for respiratory therapists to insert arterial catheters. In our experience with more than 500 catheter insertions, in which placement lasted from 1 to 20 days, superficial infection occurred in 5 percent of patients and a major complication occurred in only 1 patient. These results show that specially trained nonphysician personnel can insert arterial catheters safely when following a protocol. Similar reallocation of existing resources should increase patient care while decreasing patient care cost in most settings.