One of the characteristics of knowledge workers is their high level of mobility. The cost of labour turnover of these key resources is high in both financial and non financial terms. There is thus a need to understand what the factors are that underpin the retention cognitions of knowledge workers. Data was collected from 306 knowledge workers in full time employment representing a wide range of demographic groupings. The results showed that job satisfaction and organisational commitment do not predict knowledge workers’ proposed future length of service.Factor analysis revealed seven underlying dimensions of retention cognitions. Cluster analysis revealed nine distinct clusters of knowledge workers with regard to their retention cognitions. High levels of individualism, need for challenge and focus on personal development were demonstrated. The implications of these findings are discussed. Opsomming Een van die eienskappe van kenniswerkers is hulle hoë vlak van mobiliteit. Die koste van arbeidsomset van hierdie sleutelbronne is hoog in beide finansiële en nie-finansiële terme. Daar bestaan dus ’n behoefte om die faktore wat onderliggend is aan die retensiekognisies van kenniswerkers te verstaan. Data is ingesamel van 306 kenniswerkers in voltydse diens wat ’n wye reeks demografiese groeperings verteenwoordig. Die resultate dui daarop dat werktevredenheid en organisasieverbondenheid nie die kenniswerkers se verwagte lengte van diens voorspel nie. Faktorontleding het sewe onderliggende dimensies van retensiekognisies blootgelê. ’n Bondelontleding het nege duidelike bondels van kenniswerkers ten opsigte van hulle retensiekognisies onderskei. Hoë vlakke van individualisme, behoefte aan uitdaging en fokus op persoonlike ontwikkeling is aangedui. Die implikasies van hierdie bevindinge word bespreek.