In this talk we will discuss recent work on the modeling and algorithmic analysis of systems involving recursion and probability. There has been intense activity recently in the study of such systems [2,3,10,11,13,14,15,16,17]. The primary motivation comes from the analysis of probabilistic programs with procedures. Probability can arise either due to randomizing steps in the program, or it may reflect statistical assumptions on the behaviour of the program, under which we want to investigate its properties.