Statistics is the discipline that helps in making meaningful inferences about the real world from data. Statistics is founded on a construct of hypothesis testing, relying on a range of conditions and assumptions to estimate unbiased treatment effects and differentiate these from chance. Careful consideration of the hypothesis and the corresponding conditions and assumptions are required when formulating the research question and designing and executing a trial up to the interpretation of the results. Like surgery, statistics is a discipline to which one can devote a life of learning and practice that cannot be casually applied. It is therefore important to include a biostatistician from the start and through all phases of the project. We hereby briefly summarize some of the key statistical considerations in clinical trials in surgery (Box).