This study deals with the question of reliability of assessment of required competences. Required competences have been assessed by young knowledge workers in the labour market. Question is ‘to what extent their assessment of required competences is reliable, if it is reliable’. We used the data set of Reflex project which was carried out under the 6^th framework programme of European Union. We employed ordered probit, and OLS regression. The analyses have been realised in SPSS and Stata. We employed coherence and consistency parameters in order to draw conclusions from our findings. We found nothing contradictory to our reliability hypothesis. We feel confident to say that knowledge workers’ assessment of (required) competences is found to be, in Popperian terms, reliable to a modest extent. The fact that the respondents knew, at the time of survey, that they will not be harmed, could be regarded as a limitation to this study. We have explored only the required level of competences in this study.