Background: The Compton camera is increasingly becoming the subject of investigation for possible implementa- tion in nuclear medical imaging. It is likely to have advantages over Anger camera in medical imaging. However, very little has been done to characterize its performance for specific medical imaging techniques. There is therefore a need to fill in the gaps in knowledge relating to realistic evaluation of the viability of the camera for nuclear medical imaging. Objective: The present study has sought to explore the viability of a prototype Compton camera in breast and brain imaging. Methods: The GEANT4 simulation software was used to model the radiation transport and interactions with matter. Simulations were carried out of a Si/CZT Compton camera being used in breast and brain imaging. In order to study a challenging detection case, the volumes of two simulated breast tumours were chosen to be 0.65 mL, and embedded in the medial region of the breast. For the brain imaging, a multitracing approach was used, and imaging was done parallel to the orbitomeatal line of the brain. Results: The results suggest that the Compton camera would visualize small breast tumours of about 0.65 mL volume, placed at the medial region of an average compressed human breast. Although brain imaging using the Compton camera seems to be promising, analyses suggest however that beyond a distance difference of 2 cm between two brain tumours, there may be a need to rotate the camera around the human head for efficient brain imaging. Conclusions: It is envisioned that with further work, the Compton camera could replace the Anger camera in breast and brain imaging.