In recent years frequent genetic mutations were observed in Roumanian Oriental tobacco, variety Djebel. Most plant organs (stalk, leaves, inflorescences, flowers, capsules, seeds) were affected by the mutations. The most frequently observed teratogenetic form was stalk fasciation. Tobacco plants with flattened stalk had in most cases many more leaves than normal. Leaves were at times verticillate. Observations made from 1982 to 1995 on tobaccos presenting flattened forms showed that fasciation is hereditary. The material selected from fasciated forms was used in breeding for precocious lines with a high number of leaves per stalk (Djebel V 184, Djebel 129, Djebel 148, Djebel 267). It was noted that plants with one anomaly only were seldom found, and that most often the variability of teratogenetical forms is complex; the causes and amplifying factors of these phenomenons are not well known yet. In certain years (1986, 1987, 1989, 1994) the frequency of these mutations increased.