Using novel tools, including PhosL lectin immunofluorescence and N‐glycan MALDI mass spectrometry imaging (MALDI‐MSI), we find FUT8 underpins the biosynthesis of malignant core fucosylated N‐glycans in prostate cancer cells and using both in vitro and in vivo models, we find FUT8 promotes prostate tumour growth, cell motility and invasion. This evidence concerns the gene FUT8 and Familial prostate cancer.