The main aim of this study is to explore problematic technology use among adolescents (Internet, video games, mobiles, and television) and its association with anxiety symptoms. Furthermore, we also analysed the possible moderating role of life satisfaction in this relationship during the COVID-19 pandemic in Spain. A cross-sectional survey of 4025 children and adolescents (52% females and 48% males) between 12 and 18 years old was carried out to explore problematic technology use and its correlation with anxiety and life satisfaction after pandemic lockdown. Four multivariate regressions containing the independent variable (problematic technology use), the moderator (life satisfaction), and their interaction were entered to predict the outcome (anxiety). The moderated models were examined using SPSS PROCESS macro software (Model 1). Analyses showed significant positive correlations with anxiety and negative correlations with life satisfaction regarding problematic technology use (mobile phone, television, and internet). Both gender and age had a significant direct effect on anxiety (showing that women and older participants had the greatest anxiety). In the moderation analysis, when life satisfaction was higher, the presence of anxiety symptoms depended to a greater extent on the problematic use of technology. Our results confirm that problematic technology use is related to