Background: The Collaborative Wilms Tumour (WT) Africa Project has implemented an adapted WT treatment guideline in sub-Saharan Africa as a multi-centre prospective clinical trial. A retrospective, baseline evaluation of end-of-treatment outcome was performed for a 2-year period prior to the introduction of this guideline. The collaborative project aims to reduce both treatment abandonment and death during treatment to less than 10% for improving survival. Procedure: All participating centres obtained local Institutional Research Board (IRB) approval and implemented the adapted WT treatment guideline. End-of-treatment outcome was documented for 2 years. It was divided into alive without evidence of disease, treatment abandonment, death during treatment and persistent disease. The outcome of children enroled in the first 2 years of the prospective clinical trial has been compared to the outcome before the start of the project. Results: One hundred twenty-two patients were included in the baseline evaluation (2011–2012) and 133 in the first 2 years of the collaborative clinical trial (2014–2015). The percentage of patients alive without evidence of disease at the end of treatment increased from 52% (63/122) to 68% (90/133; P = 0.01). Treatment abandonment decreased from 23% (28/122) to 13% (17/133; P = 0.03). Death during treatment decreased from 21% (26/122) to 13% (17/133; P = 0.07). Conclusion: This collaboration, using relatively simple and low-cost interventions, led to a significant decrease in treatment abandonment and increase in survival without evidence of disease at the end of treatment.