Transfer RNAs (tRNAs) deliver specific amino acids to ribosomes during translation of messenger RNA into proteins. The abundance of tRNAs can therefore have a profound impact on cell physiology, but measuring the amount of each tRNA in cells has been limited by technical challenges. Researchers have now overcome these limitations with mim-tRNAseq, a method that can be used to quantify tRNAs in any organism and will help improve our understanding of tRNA regulation in health and disease.