Wilms tumor has a survival rate of 85% to 90% in well-resourced countries. Malawi is a country in Sub-Saharan Africa with very limited resources. We evaluated the outcome of a treatment guideline including preoperative chemotherapy, supportive care, and strategies to enable parents to complete treatment. Between 2006 and 2011, 95 patients were initially diagnosed with a Wilms tumor; 11 were later excluded due to misdiagnosis. In 31% of patients, metastases were detected at presentation. Treatment outcomes in 8 patients with bilateral tumors and 3 patients who were referred after nephrectomy are analyzed separately. Treatment failed in 51% of 73 remaining patients. Reasons for failure were: 1) incomplete treatment (7%); 2) treatment-related deaths (15%); and 3) disease-related deaths (28%) with 11% unresectable tumors or metastases after preoperative chemotherapy and 17% relapse of disease. Projected survival is 46%. Challenges remain to improve survival for children with Wilms tumor in Malawi. Earlier diagnosis would reduce disease-related deaths as numbers of unresectable disease and relapse are high. Effective strategies, including social support, to enable parents to complete treatment need to be continued. Improved supportive care and nutritional support and possibly less intense preoperative chemotherapy are needed to reduce treatment-related deaths.