Today's organisations are expected to embrace organisational agility—the ability not only to foresee opportunities and risks but also to swiftly respond appropriately. To this end, the significance of emerging information technologies (IT) in enabling organisational agility is recognised. Thus, maintaining the security of IT and related resources (i.e., information security management) has become critical for modern organisations. However, the relationship between organisational agility and information security management has not attracted sufficient attention among researchers. To address the gap in the literature, this case study explores information security challenges organisations face, as well as IT security management practices while maintaining organisational agility. The thematic analysis of the study conducted in Nigeria, based on interviews with information security experts, revealed eighteen measures that can be used to manage information security without compromising organisational agility. We argue that the measures identified will be invaluable for organisations, particularly in the finance sector.