The integration of young immigrants in the societies that host them highlights the need for the intervention of social workers to facilitate their adaptation and inclusion from an individualized diagnosis of their needs. The development of social skills in the immigrants is one of the main ways to make that integration happen, and therefore its diagnosis is fundamental. However, at present, there are no valid and reliable instruments that take into account the sociocultural factors that surround young immigrants for the evaluation of their social skills. It is for this reason that the purpose of this study was to adapt and validate a current and useful instrument for the diagnosis of such social skills to young immigrants welcomed in Spain. To do this, it was started on the choice and adaptation of The Social Skills Scale (Escala de Habilidades Sociales). Subsequently, the questionnaire was submitted to concurrent, predictive, and nomological validation processes. The construct validity was carried out by factor analysis first and second order to confirm the hierarchical structure of the scale. After validation with Exploratory Factor Analysis (n = 330), the structure was checked, and the model was later adjusted with Confirmatory Factor Analysis (n = 568) by means of structural equations. The reliability and internal consistency of the instrument was also tested with values in all dimensions above 0.8. It is concluded that this new instrument has 29 items and 6 dimensions, has acceptable validity and reliability, and can be used for the diagnosis of Social Skills in Young Immigrants.