The following article considers cyber security as an integral part of security sector reform (SSR), trying to identify some of the lessons learned from Serbia that can help when establishing a credible cyber security system. Serbia represents a telling example, as it is a country that has been undergoing significant SSR, implemented in both post-conflict and developmental context. Having in mind that Serbia is at the beginning of building its cyber security system, the article provides guidance on how to best integrate lessons learned from other SSR processes. The first part discusses the inter-linkage between SSR and cyber security institution building. The second part offers examples of initiatives implemented in Serbia during 2015, with an aim to illustrate the importance and benefits of the holistic approach to cyber security institutions building in line with the core principles of SSR. Examples present a point into an OSCE Mission project which demonstrates the importance of synergies and of a holistic, multi-stakeholder approach for effective building of functional cross-sectoral networks that can contribute to building national cyber security capacity. For its part, the cyber security capacity building initiative of government witnesses how SSR processes and actors promoting accountability can positively influence the efficiency of cyber security capacity building efforts. Another example presents how the first ever public hearing on cyber security in the Serbian Parliament was organised. It illustrates that the Parliament can be an effective starting point for a national debate on cyber security and a very efficient awareness raising tool.