Drilled cuttings re-injection (CRI) into a suitable formation by hydraulic fracturing is attracting significant attention as a friendly means of complying with environmental legislations. In CRI projects, it is essential to assure fracture containment as well as formation storage capacity which depend largely on a proper geomechanics assessment and monitoring program. This paper presents a field case on the geomechanics performance assessment and monitoring of a CRI project in Perú. The geomechanics assurance in this CRI project included the following issues: (1) geomechanical data gathering, analysis and interpretation, (2) preliminary geomechanical modeling (assessment of elastic properties, rock strength, pore pressure and stresses magnitudes and directions), (3) identification of stress and elastic barriers, (4) target zone selection, (5) periodic injectivity testing (step rate, step down and fall-off tests), (6) continuous pressure monitoring, (7) geomechanical model re-calibration using recorded pressures and injectivity data, and (8) continuous assessment of fracture containment and formation storage capacity from field data. The success of this CRI project can be examined in terms of the fracture containment and formation storage capacity for drill cutting disposal as observed from field data interpretation. Integration of log and geomechanics data, as well as geomechanics and petrophysical modeling during the planning phase, were critical in the selection of potential injection zones. Periodic injectivity tests provided valuable data for geomechanics model calibration updates. Closure pressure monitoring and proper interpretation of peak and terminal pressures are valuable tools to assess formation storage capacity in time. The results presented in this paper reveal that CRI operation is a reliable technology providing a safe and environmentally sound drilling waste management strategy.This field case presents an integrate geomechanics assurance process to illustrate the challenges, interpretations methodologies, monitoring practices, lessons learned and recommendations in the planning and deployment of CRI projects. Therefore, it represents a significant contribution to practicing engineers.