T-cells are key players of the adaptive immune system. These immune cells use their receptors to recognise and eliminate pathogens and establish immunological memory. Next-Generation Sequencing (NGS) has caused many different scientific fields to move from laborious cell experiments to high-throughput sequencing. This revolution has also made it into the field of immunology with the development of different sequencing applications. These include the possibility to profile a person’s complete T-cell receptor (TCR) repertoire be it at single-cell level or through bulk sequencing. This article provides a great introduction into the technology of TCR repertoire sequencing and gives a good overview of all available protocols.