Matrix-assisted laser desorption ionization (MALDI) is a popular technique for protein and peptide analysis. Historically, MALDI analyses have been accomplished with the sample under vacuum in combination with time-of-flight (TOF) mass analyzers, MALDI-TOF. More recently, MALDI has been performed at atmospheric pressure (AP-MALDI), in combination with various MS systems. A short overview is given on the advantages and application potential of AP-MALDI in proteomics area.