This guidance advises on core principles and frameworks for measuring results. Monitoring and results measurement (MRM) is key to successful market systems development programmes. Market systems are complex, and intervening to make them more efficient and inclusive is not a matter of implementing a fixed plan. MRM must be both rigorous and pragmatic in order to deal with this complexity. MRM in market systems development programmes must take into account two specific considerations: monitoring and measuring system-level change and its impact on the poor; and dealing with complexity and unpredictability. This guidance advises across five steps: assigning sustainability indicators; projecting how much each indicator will change by; creating a plan for collecting information to measure performance; establishing appropriate baseline information, then measuring results; analysing and using MRM information to inform decision-making and external communications. This is a preview version with the aim of eliciting comments and feedback that will be used to support further refinements and publication of the final version early in 2015. Please contact us with your comments and suggestions for consideration.