e second Critical Assessment of Small Molecule Identi cation (CASMI) contest took place in 2013. A joint team from the Swiss Federal Institute of Aquatic Science and Technology (Eawag) and Leibniz Institute of Plant Biochemistry (IPB) participated in CASMI 2013 with an automatic work ow-style entry. MOLGEN-MS/MS was used for Category 1, molecular formula calculation, restricted by the information given for each challenge. MetFrag and MetFusion were used for Category 2, structure identi cation, retrieving candidates from the compound databases KEGG, PubChem and ChemSpider and joining these lists pre-submission. e results from Category 1 were used to guide whether formula or exact mass searches were performed for Category 2. e Category 2 results were impressive considering the database size and automated regime used, although these could not compete with the manual approach of the contest winner.e Category 1 results were a ected by large m/z and ppm values in the challenge data, where strategies beyond pure enumeration from other participants were more successful. However, the combination used for the CASMI 2013 entries was extremely useful for developing decision-making criteria for automatic, high throughput general unknown (non-target) identi cation and for future contests.