In spite of the many recent reports on the damaging effects of LSD on human chromosome in vitro1,2 and in vivo3-6 and its ability to produce congenital malformations in rodents7, the teratogenic potential of this drug in humans is still uncertain. Two infants with limb malformations who had been exposed to LSD in utero have thus far been reported8,9. On the other hand, Cohen, et al.5, reported...