Purpose: To evaluate the efficacy and safety of the Surgnova Dophi™ M150E microwave ablation system in a prospective single-center observational study. Methods: A cohort of 50 patients with 77 primary or secondary liver tumors underwent CT-navigated stereotactic percutaneous microwave ablation with curative intention using the Surgnova Dophi™ M150E system. The endpoints were primary technique efficacy (PTE), number of complications, ablation defect dimensions, and sphericity index compared to previously reported findings. Results: The PTE was 97.4%, with complete ablation in 75 out of 77 tumors. Complications occurred in 10% of patients, with 4% classified as major. A comparison with previous in vivo data confirmed the reliability of the system in achieving reproducible and predictable ablation results. Conclusions: Stereotactic percutaneous microwave ablation with the Surgnova Dophi™ M150E system is safe and effective for liver tumor treatment.