The WASA detector, operating at the COSY facility in Julich (Germany) has been collecting data since 2007. The experiment allows to perform studies of light mesons, such as 0 , and rare decay processes, in order to perform precise measurements of branching ratios, determine Dalitz plot parameters, test symmetry and symmetry breaking, and evaluate transition form factors. In the experiments a proton or deuteron beam impinged on a pellet target of hydrogen or deuterium, which allows the reactions proton-proton (pp) or proton-deuteron (pd). A high-statistics sample of mesons has been collected: in the reaction pd → 3 He ,3 ×10 7 mesons were tagged at a beam energy of 1.0 GeV, while 5×10 8 mesons were produced in the reaction pp → pp at 1.4GeV. This corresponds to the production of 10 /s and 100 /s, respectively, for the two reaction processes. In the pp dataset a higher background level is found compared to the pd data set. In both cases, we identify the mesons by means of the missing mass derived from the recoil particles. A kinematic fit largely rejects the background in our analysis. The advantage in using the pp dataset is that the production of mesons is almost a factor of 10 higher than in the pd fusion to 3 He. As we plan to measure the branching ratios of very rare processes, high statistics is needed. A summary of the recent activity on the study of light mesons with WASA-at-COSY here is given.