This paper aims to establish whether there was a gap in biological living standards between urban and rural areas in late nineteenth-century Catalonia, and if so, to determine its extent. The study makes use of a large new dataset based on military records for the cohort of males born in the year 1890 and enlisted in the year 1911. By combining individual heights with information at municipal level, we conclude that the 1890 cohort of conscripts living in rural areas were shorter than those that resided in towns and cities with populations of more than 20,000 people. We also hypothesise about the reasons why urban dwellers in late nineteenth-century Catalonia were taller than their rural counterparts by considering the potential role of rural–urban migration, improvements in public sanitation and health care, and progresses in the quantity and quality of food availability for urban dwellers.