Several researchers have found that media exposure through books or electronic media contribute to preschoolers' development. However, research with behavioral measures and during the first years of life have not been carried out in Latin American contexts. The aim of the following research was to evaluate the relations between media exposure through electronic media and books with joint attention skills and temperament (i.e., effortful control, surgency and negative affect) during the first year of life. A free play session was carried out, where the number of mother-infant interaction behaviors were assessed. Findings state that only the amount and the frequency of the use of books at home between caregivers and infants were positively associated with the behaviors of joint attention and surgency. Conclusion denotes that books would probably be associated with more infant interactions and higher SES, mediating in the promotion of cognitive development from the first months of life.