The ozone soundings performed at Payerne with the Brewer-Mast sonde constitute one of the longest time series available in Europe. Instrumental and operating changes have been responsible for inhomogeneities in this time series. This report gives an overview on the historical documentation, as well as the re-evaluation procedures and the homogeneity checks performed. It also provides an ozone climatological overview and an updated trend analysis for the whole measurement period between 1967 and 2000