ABSTRACT: ♦ BACKGROUND: Peritoneal dialysis (PD) is recommended for adults with residual kidney function and without significant comorbidities. However, peritonitis is a serious and common complication that is associated with hospitalization, pain, catheter loss, and death. This study aims to describe the beliefs, needs, and experiences of PD patients about peritonitis, to inform the training, support, and care of these patients. ♦ METHODS: Qualitative semi-structured interviews were conducted with 29 patients from 3 renal units in Australia who had previous or current experience of PD. The interviews were conducted between November 2014 and November 2015. Transcripts were analyzed thematically. ♦ RESULTS: We identified 4 themes: constant vigilance for prevention (conscious of vulnerability, sharing responsibility with family, demanding attention to detail, ambiguity of detecting infection, ineradicable inhabitation, jeopardizing PD success); invading harm (life-threatening, wreaking internal damage, debilitating pain, losing control and dignity); incapacitating lifestyle interference (financial strain, isolation and separation, exacerbating burden on family); and exasperation with hospitalization (dread of hospital admission, exposure to infection, gruelling follow-up schedule, exposure to harm). ♦ CONCLUSIONS: Patients perceived that peritonitis could threaten their health, treatment modality, and lifestyle, which motivated vigilance and attention to hygiene. They felt a loss of control due to debilitating symptoms including pain and having to be hospitalized, and they were uncertain about how to monitor for signs of peritonitis. Providing patients with education about the causes and signs of peritonitis and addressing their concerns about lifestyle impact, financial impact, hospitalization, and peritonitis-related anxieties may improve treatment satisfaction and outcomes for patients requiring PD.