The increase in cybersecurity threats and the challenges for organisations to protect their information technology assets has made adherence to organisational security control processes and procedures a critical issue that needs to be adequately addressed. Drawing insight from organisational theory literature, we develop a multi-theory model, combining the elements of the theory of planned behaviour, competing value framework, and technology—organisational and environmental theory to examine how the organisational mechanisms interact with espoused cultural values and employee cognitive belief to influence cybersecurity control procedures. Using a structured questionnaire, we deployed structural equation modelling (SEM) to analyse the survey data obtained from public sector information technology organisations in Nigeria to test the hypothesis on the relationship of socio-organisational mechanisms and techno-cultural factors with other key determinants of employee security behaviour.