This study aimed to investigate the differential relationship between Temperament, Executive Functioning (EF) and Media Use Motivations and the frequency of two kinds of Media Multitasking (MM) in early adolescence. Results showed differential roles of temperamental Effortful Control, Negative Affectivity and Affiliativeness in predicting academic MM and MM with other media activities. Greater EF deficits in inhibition predicted more frequent MM with other media activities and fewer EF deficits in monitoring predicted more frequent academic MM. Significant relationships have also been found between some Media Use Motivations and MM. These results are discussed in the context of the changes in adolescents' relationship to technology that have been brought by the COVID-19 pandemic and persist after its end. Implications also center on the need to consider the context and factors that generated MM in the first place to better understand MM effects.