Two patients with cancer requiring removal of specific impalpable lymph nodes for full pathological analysis underwent ultrasound-guided lesion localisation and marking with a low-activity I-125 seed. A gamma probe was used in theatre to localise the signal from the seed and guide excision. Successful removal of the lesions was confirmed with the probe and by specimen radiography. Radioguided Occult Lesion Localisation using I-125 Seeds ("ROLLIS") provides a method of precisely marking impalpable lesions for surgical excision. Copyright 2014 BMJ Publishing Group. All rights reserved.