Objective: to understand the nursing practices related to peripheral venipuncture and to analyze the incidence of complications in patients with venous catheters. Method: mixed design, involving: case study, sectional study, cohort study and focus group. The sample consisted of nurses and patients from a medical clinic in Portugal. Thematic analysis and descriptive statistics were performed. Results: stressors capable of influencing nursing practices were identified, including: the decisions of the medical team, the age and characteristics of the venous network of the patient, the availability of other catheters in the institution, the low level of knowledge of nurses regarding the care of patients in the insertion, maintenance and removal of the peripherally inserted central venous catheter. The following complications and their respective incidences were documented in patients with peripheral venous catheters: phlebitis (22.2%), obstruction (27.7%), fluid exiting through insertion site (36.1%), infiltration (38.8%) and accidental catheter removal (47.2%). Catheter obstruction with an incidence of 22.2% was only observed in those who used the peripherally inserted central venous catheter. The following benefits were observed with the use of the peripherally inserted central venous catheter: safe administration of drugs; pain reduction, number of venous punctures and complications. Conclusions: the peripherally inserted central venous catheter is presented as a valid and viable alternative that can improve the quality of nursing care and the safety and well-being of patients.