The audiograms and CT scans of three children with a bilateral congenital mixed deafness are presented. Two children underwent an exploratory tympanotomy revealing a fixed stapes footplate: a perilymph gusher arose during platinotomy in both cases. The gusher was controlled successfully with a large fat graft in both children, and hearing remained unchanged. Two of the children were brothers: they had no other deformities except an enlarged fundus of the auditory canal on CT scans, and no clearly defined bony barrier to the vestibule, suggesting a cerebrospinal fluid fistula. Neither a patent nor an abnormal cochlear aqueduct could be detected in all three cases. It is likely that the three patients present an X-linked mixed deafness syndrome with fixation of the stapedial foot plate and perilymph gusher. A classification of congenital perilymph-CSF shunts is proposed.