Resumen: The objective of this study was to analyse, from a long-term perspective, the factors determining the process of the internationalisation of the Spanish agrifood industry. The paper concentrates on the empirical verification of the existence of a home market effect in the food and drink industries in Spain and on the effects on trade flows of integration into the European Union. With this aim in mind, we took into account the latest contributions to the estimation of the gravity equation for a sample of export flows from 13 agrifood subsectors between 1970 and 2012, with a destination of 175 markets. From the results of the study the existence of the “home market effect” stands out as the determining factor of the increasing process of internationalisation in the majority of the subsectors of the food industry. On this point, the presence of this effect is remarkable in the most dynamic industries, where the process of restructuring caused by the development of the internal market was more intense. Furthermore, the influence of the process of European integration has been shown by the literature to be a very important factor. Our results qualify in part the results of previous studies, since the positive effect appeared later than expected. The positive effects did not appear until the completion of the process of transition by the dismantling of the barriers established in the treaty of accession to the European Union. Idioma: Inglés DOI: 10.5424/sjar/2015133-7501 Año: 2015 Publicado en: Spanish Journal of Agricultural Research 13, 3 (2015), e0104 [13 pp] ISSN: 1695-971X Factor impacto JCR: 0.76 (2015) Categ. JCR: AGRICULTURE, MULTIDISCIPLINARY rank: 24 / 57 = 0.421 (2015) - Q2 - T2 Factor impacto SCIMAGO: 0.385 - Agronomy and Crop Science (Q2)