The use of elastography for the visualization of thermal lesions in biological soft tissue in vitro was investigated. Thermal lesions were created in samples of postmortem ovine kidney using a surgical neodymium: YAG (Nd:YAG) laser. The kidney samples were cast in gel, and elastographic images of the lesions were constructed using sonographic information and external markers to locate the region of interest. Gross pathology of the kidney samples confirmed the dimensions of the lesions. Good correlation between the lesion length along the laser fiber axis and maximum diameter measured off of the fiber axis determined from elastographic images and gross pathology photographs was found.