Twenty patients suspected of meningeal carcinomatosis (MC) secondary to small cell carcinoma of the lung were evaluated by myelography and by cytologic examination of cerebrospinal fluid (CSF). In 4 patients both investigations demonstrated MC. Four had positive cytology but a negative myelogram. Five patients had a positive myelogram but negative cytology. Thus 13 of the 20 patients had MC diagnosed by one or both of these investigations. Two additional patients suspected of MC were studied; both had positive myelography, but cytologic examination of CSF was not performed in either case. Six patients underwent autopsy with microscopic examination of the spinal cord; in all cases post-mortem findings supported myelographic findings. In conclusion, myelography is useful in the evaluation of patients suspected of MC secondary to small carcinoma of the lung and complements the diagnostic role of CSF examination.