With the advancing sophistication of innovative human organoid models gathering pace and the well-characterised structural differences between human and mouse placental architecture, there is legitimate debate around the ongoing relevance of rodent models in placental research. Herein I posit much can still be gleaned about conserved aspects of placental formation and function using transgenic mouse models, with the caveat that context is paramount. Two critical aspects of rodent models still offer significant advantages for placental research; the ability to characterise the impact of genetic manipulations in vivo and the tractability of a system that retains embryonic connections, allowing fetal growth and development as a readout of placental manipulations and function. I will present some of our work highlighting the utility of transgenic mouse models to investigate placental transport, the connection between placental and heart development, and the lineages of placental progenitors.