Background <p>Localisation of non-palpable soft tissue lesions remains challenging, particularly in previously treated or anatomically complex regions. Magnetic seed (Magseed^®) localisation, widely used in breast surgery, offers a radiation-free alternative to wire or radioactive methods; however, its use in non-palpable soft tissue lesions has not yet been described in the literature. This paper presents the experience of a tertiary cancer centre with the use of magnetic seed in the intraoperative localisation of non-palpable soft tissue lesions, outlining its feasibility, accuracy, and safety.</p> Methods <p>All patients who underwent excision of non-palpable soft tissue lesions localised with Magseed^® between February 2021 and December 2024 at a tertiary cancer centre were retrospectively reviewed. The primary endpoints were successful placement and retrieval of the seed. Secondary outcomes included dislocation, margin status, operative time, and perioperative complications.</p> Results <p>Thirty-one seeds were placed in 27 patients (median age 67 years). The median lesion size was 15&#xa0;mm, and the median depth was 21&#xa0;mm. All seeds were correctly positioned under ultrasound guidance without complications. The detection rate was 100%, and negative margins were achieved in 97% of cases. Minor perioperative complications occurred in 6% of cases. Operative time was not correlated with lesion depth or BMI but was shorter in lymph node localisations (<i>p</i> = 0.079).</p> Conclusions <p>Magnetic seed localisation is a safe, effective, and radiation-free method for non-palpable soft tissue lesions. This pilot series provides the first clinical evidence supporting its feasibility beyond breast surgery and highlights its potential to enhance precision in oncological procedures.</p>