The occurrence of the most important mycotoxins (deoxynivalenol, fumonisin B and B, aflatoxins B, B, G, and G, ochratoxin A, zearalenone, T-2, and HT-2 toxins) was determined in 64 extruded cat foods purchased in Italy through ultra-performance liquid chromatography coupled with tandem mass spectrometry. Deoxynivalenol and fumonisins were the most common contaminants (quantified in 80 and 95% of the samples, respectively). Conversely, aflatoxins B, G, and G were not identified in any sample. Some cat foods exceeded the regulatory limit for aflatoxin B ( = 3) or the guidance values for zearalenone ( = 3), fumonisins ( = 2), ochratoxin A ( = 1), and T-2 ( = 1) recently established for pets in the European Union. A widespread co-occurrence of mycotoxins was observed (28, 42, and 8% of the samples contained quantifiable amounts of two, three, and four mycotoxins, respectively). This study describes criticisms regarding the mycotoxin issue in pet food and suggests an improvement of the monitoring of the pet food chain.