AbstractA case of heterochromia iridis and Horner's syndrome is reported in a 7‐year old girl with paravertebral neurilemmoma. These clinical findings can be useful in the early diagnosis of mediastinal tumors in the paravertebral axis. While typically associated with neuroblastoma, these findings can be due to tumors which are inately benign — in this case neurilemmoma. The mechanism for heterochromia is briefly discussed.