This article focuses on the under-researched topic of the use of Twitter by members of parliament (MPs) in Latin America. There have not yet been any thorough comparative studies on this topic, and the majority of publications on the region focus on single case studies. Previous studies have primarily concentrated on presidents, or in the case of MPs, on specific case studies. A total of 2,353,138 tweets were accessed via the Twitter API, and 3,215 MPs were examined. Regression models and correlations were used to answer research questions, and the main variables examined concerned individual characteristics of MPs (gender and age) and socioeconomic indicators of the country (number of people on Twitter, internet access, Human Development Index - HDI). As a result, this paper offers a report on how MPs in Latin America are currently utilizing Twitter. While his social network is used by more than 90% of MPs in some countries (Argentina, Colombia, Ecuador, El Salvador, Peru, and Uruguay), there are countries where fewer than half of MPs use it (Bolivia, Honduras, and Nicaragua). The results show that female MPs are more likely than male MPs to use Twitter. In addition, Twitter is being adopted more by younger MPs. Other results show that country characteristics such as internet penetration, Twitter population, and the HDI are significant predictors regarding the adoption and use of Twitter by MPs. These results are consistent with assumptions based on cost-benefit calculus. Thus, it does not make as much sense for politicians to adopt Twitter in countries where there are less people on Twitter and low internet penetration. In particular, if politicians want to be elected or inform citizens about their activities, they have an opportunity to reach voters through Twitter. However, this is only true if Twitter is used in their countries.