Two Proficiency Testings (PTs) involving eighteen laboratory participants from 10 Countries have been conducted in 2014 for the simultaneous determination of deoxynivalenol, fumonisins B 1 and B 2 , zearalenone, T-2 and HT-2 toxins, ochratoxin A and aflatoxins B 1 , B 2 , G 1 and G 2 in maize and of deoxynivalenol, zearalenone, T-2 and HT-2 toxins and ochratoxin A in wheat, respectively. The aim of PTs was to check next to the laboratory performance the state-of-art of the LC–MS multi-mycotoxin methods used by participants. In addition, the trend of performances of LC–MS methods for multi-mycotoxin determination in maize together with method-related issues was assessed by comparing three PTs organised over the years 2011–2014. Data showed the improvement of laboratory performances with the overall acceptable z-scores that progressively increased from 59% in 2011 PT to 85% in 2014 PT, while the rate of unacceptable z-score decreased from 25% in 2011 PT to 11% in 2014 PT. [ABSTRACT FROM AUTHOR]