Whole genome sequencing (WGS) is regarded by many as the pinnacle of contemporary molecular genetic testing, and has only been possible because of the rapid development and roll-out of next-generation sequencing technologies. It provides a phenotype-agnostic analysis of the genome and has important advantages compared to other techniques including a consistent coverage across the coding and non-coding genome, the application of high resolution homozygosity mapping and the ability to detect and highlight structural variation. Realising this potential and with a bid to sequence 100,000 genomes, the UK rolled out the 100,000 Genomes Project as a proof of concept of integrating genomics in the national health service. Participants with cancer and rare diseases enrolled in the project whose infrastructure comprises of a central national biorepository and 13 regional genomic medicine centres where clinicians, geneticists and other scientists work as part of a multidisciplinary team. Amongst participants are also patients with genetically unclassified Charcot-Marie-Tooth disease who have benefited substantially from improved diagnostic rates and many more stand to benefit as the analysis of genomic data is ongoing. WGS is an important tool as we head towards more personalised medicine and in our quest to improve public health and treat and where possible prevent disease.