This article examines the evolution of Sismondi’s price theory as well as his concept of market from 1803 to 1838. Sismondi’s early 1803 price theory in terms of supply and demand is first examined and contrasted with that of Smith in the Wealth of Nations. The progressive alterations brought to this initial formulation are discussed with the help of the relevant chapters from Nouveaux Principes ([1819] 1827) and from Études (1836–1838). In price theory terms, throughout the years Sismondi grew more and more skeptical about the process through which these prices would come about. Connecting this analytical issue with his concept of republican justice, he comes to the conclusion that a market economy characterized by unlimited competition will never lead to a socially desirable solution: such an order is neither efficient, nor natural or spontaneous and political economy is not morally neutral. In short, for Sismondi, the market never stood alone while, for him, the Ricardian approach gave nearly exclusive pride of place to market in the pursuit of wealth and happiness.