This chapter focuses on how we can best predict the future health of patients, known as prognosis. This encompasses areas such as risk prediction and predicting response to treatment. A clinical opinion piece summarises the role of prognosis in clinical care and highlights the areas where AI has already had an impact in this area. The technical section summarizes the state-of-the-art in outcome prediction, focusing on three clinical applications as exemplars: predicting response to cardiac resynchronization therapy (CRT), predicting outcome in atrial fibrillation and risk stratification in ventricular arrhythmia. A practical tutorial reinforces these concepts by taking the reader through a simple outcome prediction task based on cardiac morphology. The closing clinical opinion piece highlights areas where AI could impact prognostic tasks in the future.