In a proof of concept perspective, Rapid Evaporative Ionisation Mass Spectrometry (REIMS) was explored for the direct analysis of meat samples from beta-agonist treated livestock. In this context, the combination of REIMS with untargeted metabolomics was investigated to identify carcasses from treated animals on the basis of a modification of indirect metabolites profile. The REIMS analysis generated specific lipid profiles which enabled the differentiation of meat samples collected from pigs treated with ractopamine via their feeding regime. Furthermore, the strategy was found successful when tested on different muscle types (loin, shoulder and thigh), which further expands its applicability. Classification performances were greater than 95% accurate which fully answers requirements of a screening strategy. This research indicates that REIMS implemented in an untargeted-metabolomics workflow can be considered as a high-throughput and accurate strategy for real-time meat classification in relation to ractopamine (and wider beta-agonists) treatment in pig production. This approach may subsequently be implemented as a rapid screening test, at the slaughterhouse or at border inspection points, to detect such practice.