It has been a longstanding question how stars are packed or distributed in the universe. Here we show that the spatial distribution of stars follows some geometric rules although there may be local inhomogeneities. The topological and metric properties of their Voronoi tessellations exhibit a lognormal distribution. Moreover, these distributions can be connected with those established for the packing of spheres, corresponding to the loosest packing state. The findings provide a new angle to understand the packing structure of stars in the universe. Display omitted •The packing of stars is studied in terms of the topological and metric properties of the Voronoi tessellation.•The spatial distribution of stars is shown to follow some geometric rules, quantified by the lognormal distribution.•The packing of stars can be linked to the packing of spheres, corresponding to the loosest packing state.