This article fits into the problematic aspects of citizen participation and involvement.Its main aim is presenting the concept of crowdsourcing maturity of public organisations.Crowdsourcing is a unique on-line activity and participation in which an organisation invites the virtual community to collaborate and act.It should be underlined that the taken up issue of public organisation crowdsourcing maturity is a novum.The existing research focuses on commercial organisations.As a consequence there is a lack of complex publications or extensive research which deal with this subject.The article presents a review of research concerning crowdsourcing maturity.Based on it, an original method of measuring public organisation crowdsourcing maturity has been proposed.The article is also a starting point for further research, in particular testing the proposed tool.Since 2008 a growing importance of crowdsourcing and tendencies to implement it by public organisations in their activity have been observed.Moreover, crowdsourcing in public organisations is becoming an efficient and effective practice which can bring a lot of benefits to these organisations.First, it enables reaching for valuable knowledge of the virtual communities and thanks to that generating new ideas or developing innovative solutions to various problems.Second,it increases the capacity of citizens’ participation in public life,their involvement,and a feeling of ability to make changes in their immediate surroundings.Crowdsourcing in public organisations has ceased to be solely a trend, but it is becoming a unique strategic model of acquiring and attracting the virtual community which is interested, motivated, and possesses valuable knowledge.Practice shows, however, that identical tools or solutions applied in different organisations do not yield the same positive results. In some public organisations, attempts to implement crowdsourcing end in failure.Organisations demonstrate a different ability to apply crowdourcing.Not all organisations are able to manage crowdsourcing in an appropriate way.It may be said that that are various levels of crowdsourcing maturity.In the literature it is suggested that starting to implement and use crowdsourcing by the organisations should be preceded by significant organisational changes related to the processes,infrastructure,and organisational culture–it is only then when the organisations may include crowdsourcing in their strategies and consider its strategic application.Therefore, it can be assumed that the more numerous the areas, necessary for realising crowdsourcing,realised by the organisation are,the higher is the degree in which it deserves being called mature crowdsourcing wise.Achieving maturity is connected with improving specific abilities,characteristics,and capabilities of the organisation in a given area,which increases effectiveness and readiness to perform tasks,customer satisfaction,reduces costs, and contributes to building the organisation’s competitive advantage.The more numerous the modules in which the organisation realises the requirements are,the higher is the degree in which it deserves being called mature crowdsourcing wise.The evaluation of crowdsourcing maturity may constitute a set of principal requirements and framework guidelines for a given proces.It is possible to evaluate the effectiveness of processes’ analysis and also identify those which should be modified or improved.According to the logic of crowdsourcing maturity, it is possible to distinguish an organisation which is immature crowdsourcing wise and an organisation which is fully mature crowdsourcing wise as well as any intermediate forms.