Critical thinking is fundamental to 21st century learning and has thus become an important part of the technology curricula in many countries. Critical thinking draws on the ability to examine, analyse, interpret and evaluate, as well as asking questions and participating in discussions about risks and benefits of different technological solutions. An important task for teachers is to support young children in developing these skills. Students on a Swedish primary school teacher education programme were given an assignment inspired by the concept of ‘disruptive technologies’ (Barlex, Givens & Steeg, 2016; Manyika, Chui, Bughin, Dobbs, Bisson & Marrs, 2013), choosing from one of nine disruptive technologies and searching for information. The list was created on the grounds that these are technologies that are likely to have a significant effect on the students’ lives in a not too distant future. Based on the information found, the students were to critically analyse the technology they had chosen. This case study was performed through a thematic analysis of 120 assignment texts. The analysis showed that some of the suggested technologies were chosen more often than others. Autonomous cars came top, although robots in elderly care were the most frequently chosen technology among female students. The students performed well in the searching and collecting process. They found information about pros and cons for their chosen disruptive technology. However, the analysis also showed that the students had difficulty evaluating and problematising the information they had found. In their conclusions they did not change their original point of view. Even though they found more negative aspects of a new technology, they accentuated the positives.