T2 mapping is commonly used in the evaluation, progression and diagnosis of cartilaginous regions of the knee. Objective: To develop a tool (open source free software) for the study of T2 relaxometry. Methods: We performed a pilot test through a knee image of a volunteer using a 1.5 T MRI in order to developed a MATLAB program to generate the T2 maps. Results: We developed a software and named it Mapas T2. We obtained the T2 maps in the clinical routine of a group of three patients. In the comparison with the three free programs, no significant difference was found between the values of the T2 maps. Conclusion: The developed software, now made available on the link https://mapast2.site123.me/, allows generating T2 maps of cartilaginous structures of the knee in an agile way and with usability features.