Led by Jana Obšteter Summary Genomic selection has doubled the genetic gain in dairy breeding. Small populations still struggle with its implementation mainly due to the lack of financial resources and a sustainable strategy. In this project, we explored via simulations in four steps how to implement genomic selection in small populations to ensure short‑term and long-term genetic gain in the local environment. First, we showed that small populations can increase short-term genetic gain by implementing genomic selection of sires, performing a faster turn-over of sires, and increasing the intensity of sire selection. Second, we showed that we can increase long-term genetic gain, measured as the efficiency of converting genetic variability into genetic gain, via the hybrid use of progeny and genomically tested sires, and faster turn-over of sires. This improves the sustainability of the breeding programs. Third, we showed that every breeding program can implement genomic selection via optimization of investment in phenotyping and genotyping. We showed that even a small reallocation of funds from milk recording to genotyping increases genetic gain regardless of the relative price of phenotyping and availability of an initial training population. Fourth, we showed that small populations can increase their genetic gain by importing genetic material. However, the increase should be weighted against the decreased contribution and value of domestic selection. Our results reveal the potential of genomic selection for breeding programs in small dairy cattle populations. This article was published on 2024-09-02