Abstract The cobaltite BaCo2(AsO4)2 (BCAO) is a good realization of the quasi-2D system in which the Co 2 + ions form a magnetically frustrated honeycomb lattice with magnetic moments mainly confined in the basal planes. Below T N = 5.35 ± 0.5 K , the ground state structure is described by an incommensurate propagation vector k ≈ ( 0.265 , 0 ,- 1.33 ) and the magnetic excitation spectrum displays a resolution-limited energy gap Δ 0 ≈ 1.45 meV at q = 0 . No magnetic excitations emerging from q = k could be detected, contrary to what would be expected for a simple helimagnetic ground state. In order to understand these puzzling results, we have recently re-investigated the magnetic structure and excitations in BCAO using spherical neutron-polarization analysis.