This thesis focuses in the evaluation of Threat Intelligence Platforms (TIPs). TIPs are security tools that use global security data to help proactively identify, mitigate and remediate security threats. New and continually evolving sophisticated threats are surfacing every day making the processes of detection and mitigation far more complicated than some years ago. So it’s obvious that the need for more and more intelligent security tools has become imperative. Thus, organizations were encouraged to change their traditional defence models and to use and to develop new systems with a proactive approach. Such changes are necessary because the old approaches are not effective anymore to detect advanced attacks. Also, the organizations are encouraged to develop the ability to respond to incidents in real-time using complex threat intelligence platforms. This thesis is separated in three big sections. In the beginning we are going to discuss what threat intelligence is and how it is used by researchers and organisations. Subsequently a concise analysis and description of four open source and widespread TIPs will be presented. The platforms I chose are: MISP (Malware Information Sharing Platform), OpenCTI (Open Cyber Threat Intelligence Platform), CIF (Collective Intelligence Framework) and CRITs (Collaborative Reasearch Into Threats). Finally, at the last section I will present the evaluation of these platforms according to specific criteria along with some key findings and limitations that extracted from the analysis.