Immersed in an intense and increasingly digitized world, determining the relationship between the use of ICT in the learning process and educational outcomes takes on special relevance to guide educational policy decisions in a reasoned way. The objective of this study is to estimate the effect of the use and availability of Technologies of Information and Communication (ICT) at school and at home on academic performance. For this purpose, we apply a hierarchical lineal regression model approach with data from PISA 2015. PISA 2015 contains a brief specific questionnaire for ICT that is done voluntarily in some of the participating countries in PISA, this being the case of Spain. The results show differences in the sign of the impact according to the ICT variable used. The positive impact of ICT use is associated with the use for entertainment at home and with the students’ interest in ICT. However, the use of ICT for schoolwork at home and the general use of ICT by students in schools have negative effects on the learning process. Another outstanding result is the magnitude of the coefficient for the relation between the age of beginning in the use of ICT on the scores in the three competences. The higher the age, the lower the score achieved. The results of the regressions by tertiles of performance show that ICT can also play an important role to improve the academic performance of the students with the worse results. Finally, some control variables related to students, home and location are also relevant in our models.