Effectiveness of positive punishment (inflict something unpleasant to reduce unwanted behaviour) is subject to conditions such as timing, schedule etc. Inappropriate use may impair dog welfare and is suspect of causing problem behaviour. Our aim was to quantify owners` use of positive punishment and to explore relationships of appropriateness of positive punishment with problem behaviour and training engagement. Therefore, we surveyed Viennese petdog-owners via questionnaire sent by post in January 2007. It contained questions regarding schedule, intensity and use of a warning signal in order to categorise owners according to the appropriateness of their use of positive punishment. Altogether 1345 questionnaires (return rate=28%) were analysed using Oneway-ANOVA, Cross-Tabulations and Linear Regression. 28.9 % of the owners declared that they do not use positive punishment, 17.2% gave inconsistent answers and 43.6% constantly reported to use positive punishment. We concentrated on the latter in further analyses. Inappropriateness of positive punishment was linked with an increase in reported frequencies of aggression (F(3, 506)=5.09, p=0.002) and fear (F(3, 509)=6.18, p=0.000) in dogs. Moreover, decreased obedience (F(3, 498)=36,80, p=0.000) and a lower tolerance of close physical contact with the owner (chi2=22.91, p=0.000) was found in inappropriately punished dogs. Frequency of dog training, a possible confounder, was related to appropriateness of punishment (chi2=30.17, p=0.003) and dog behaviour: a higher frequency of dog training was associated with increased obedience (F(4, 494)=11.87, p=0.000) and decreased fear (F(4, 505)=5.12, p=0.000). Nevertheless, appropriateness of punishment showed to be the better predictor for obedience (beta=0.395, t=9.78, p=0.000) and fear (beta=-0.161, t=-3.67, p=0.000) in dogs. We conclude that inappropriate use of positive punishment has the ability to increase aggression and fear. It can lower the tolerance of close physical contact with the owner and decrease obedience. Therefore we see well-being of owners and public as well as dog welfare put at risk.