There is a need for high quality impact evaluation in conservation biology. In response to this need there is a growing body of work on how best to evaluate conservation interventions. However, often these methods are often too time consuming or resource heavy for small NGOs to carry out. I trialled the Theory of Change of approach to impact evaluation using the Saiga Conservation Alliance’s work in Uzbekistan as a case study. I used the approach to construct diagrammatic representations of the Theories of Change focusing on the threat of oil and gas companies and poaching to vulnerable populations of saiga antelope (Saiga tatarica) on the Ustyurt plateau. I used these Theory of Changes and the relevant assumptions and accompanying evidence as part of an evaluation plan to set priorities for monitoring and data collection. The results showed that The Theory of Change approach is a useful and insightful one that is suitable for small NGOs to use in impact evaluation. It was also revealed that the approach holds lots of potential for future use by the Saiga Conservation Alliance and more broadly in the field of conservation as a powerful tool for planning, communication and evaluation.