Lumbar sympathectomy remains popular in the treatment of a variety of painful and circulatory conditions of the lower extremities. Although percutaneous chemical lumbar sympathectomy (PCLS) under radiographic guidance is minimally invasive and has decreased the need for open surgical sympathectomy, inadvertent damage to neighbouring structures is a matter for concern. We report the case of a 38-year-old man with thromboangiitis obliterans who had PCLS under radiographic guidance for relief of ischaemic rest pain that was complicated by necrotic disruption of the left pelviureteric region. The kidney was salvaged with an ureterocalycostomy and he remains well 4 years later. Such complications point to imprecise and unpredictable spread of the injected chemical too far beyond the needle tip. It is possible that such complications are often under reported and, therefore, not taken into consideration during informed consent. Precise neurolysis with laser and radiofrequency may be a safer alternative.