Technological change often promotes higher complexity which in turn increases controllability issues and likelihood that something will go wrong.

This article explores relationship between systemic importance and complexity of information systems of banks which operate in the Republic of Croatia.

Based on a bank survey performed in 2012 by the Croatian National Bank, 25 variables which might indicate higher level of information system complexity were identified and correlated with banks’ sizes.

 High level of association was found. This revelation could have implications on banking supervision and, generally, on design of banks’ information systems and related control environment.