We are in a very exciting era of precision cosmology. Most of the standard cosmological model parameters have now been measured with per cent level precision, including the density of visible matter in the Universe. As we continue to push the precision of our cosmological understanding, there is every chance that we’ll uncover a hint of physics beyond the Standard Model. In this talk, I will present an overview of the latest measurements of the primordial element abundances, which provide a window to study the physics of the Universe a few minutes after the Big Bang. In particular, I will discuss the primordial abundances of deuterium and helium. I will also present a novel measurement of the helium isotope ratio of the Milky Way, and discuss the prospects for determining the primordial helium isotope ratio in the near-future.