This book addresses the relationships between stratification and social mobilities in Argentina today, using an ethnographic study on class relations in the San Telmo neighborhood (located in the country’s capital, Buenos Aires). Relying on the extended case method, we narrate Ramiro’s life history. He is a worker who has lived in the neighborhood for forty years, striving to carve out his career through a network of micro- and macrosocial relationships that frame his daily conflicts. We start by synthesizing the debates on class internationally and in Argentina, establishing the study’s initial theoretical frameworks, and describing the methodology used. We then reconstruct Ramiro’s life, starting from his experiences in his home province of Tucumán and narrating his migration to and arrival in Buenos Aires, his settling in San Telmo, his labor insertion, and the class conflicts that he currently experiences. We conclude by presenting a tentative anthropological conceptualization of class.