The aim of the research is to find out whether young European youngsters in the age group 18-27 years working in a multinational company in Dublin, experience cognitive dissonance after purchase of fashion clothing like jeans, tops, shirts, trousers, party wear, skirts etc. The research also investigates whether all consumers experience cognitive dissonance or dissonance is experienced differently by different groups of young consumers. Further the impact of consumer behaviour on cognitive dissonance and the difference in consumer behaviour between consumer segments with varying dissonance levels were statistically analysed. The current study will be one of the few researches on the construct of cognitive dissonance related to fashion clothing. The research concluded that the majority of the young European consumers experienced 'wisdom of purchase' dimension of cognitive dissonance. Statistical analysis revealed that there were two segments of respondents with significantly different dissonance levels and they were named as 'High dissonance group' and 'Low dissonance group' respectively. 15 attitudinal and behavioural factors were used to study the consumer behaviour. Statistical analysis proved that there was significant difference in the attitudinal and behavioural factors between different consumer dissonance segments. The striking finding of the research is that the cognitive dissonance did not have any statistically significant impact on repeat purchase, active loyalty or complaint behaviour.