The introduction of the Landmark midline catheter (Menlo, Co., CA) brought an alternative to central line catheter placement for prolonged intravenous access. The study was initiated in 1993 to observe for complications, including hypersensitivity-like reactions. The authors hypothesized this i.v. modality would decrease the need for central i.v. lines and accompanying complications. At the time of catheter insertion, the i.v. team nurses completed a survey form that included demographics, underlying disease, and risk factors for infection. The catheter tip was cultured at the time of removal. In the second phase of the study, the authors focused specifically on hypersensitivity-like reactions. During a 2-year period, 248 patients had 334 midline catheters. Patient ages ranged from 23 to 98 years (mean age, 65 years). The bacteremia rate was 0.3%; the colonization rate was 0.9%. Factors associated with infection/ colonization included: length of time in place, chemotherapy, and lack of antibiotic administration. In the second phase of the study, during which an additional 170 catheters were placed in 131 patients, no hypersensitivity-like reactions were noted. The midline catheter appears to be a safe method of i.v. fluid administration for patients with limited peripheral vein access who need extended i.v. therapy.