Abstract This paper uses 4080 observations from the Swedish Maritime Administration (1996–2001) to test how vessel’s characteristics influence the length of time between two port state control inspections (PSC) along with the number of deficiencies detected during PSC. It also investigates whether a ship that has undergone PSC inspection at a certain time exhibits a reduction in the total number of deficiencies detected during the next control. Estimates from Poisson models stress that the age of the vessel, ship type, and flag of registry appear to be significant predictors. Subsequently, the analysis on 874 repeated inspections shows that following a PSC inspection, the reported deficiencies during next inspection is reduced by 63%.