Summary The present investigation study the morphological and cytogenetic effects of Calotropis procera extract on Vicia faba L. The control plants being normal while treated ones are significantly affected. Four concentrations (5, 15, 30, 60%) of this extract were applied for 3 duration time. For treated seeds, low doses caused increase in mitotic indix (MI) and exhibit stimulatory effect on percentage of germination and plant height. On the other hand high concentratiosn gave rise to substantial reduction in MI, percentage of germination and plant height and all were found dose and time dependent. In contrast, all parameters tested for treated roots were found negatively affected with no exception and found more harmful and effective compared to seed treatment experiment. Various types of mitotic and meiotic abnormalities were observed. Their percentage of these abnormalities was also found dose and time dependent. Stickiness type was found more frequent compared with other types. The extract also affect chromosome association during meiosis. Chromosome pairing, chiasma frequency and pollen fertility were found negatively affected and dose dependent. The present data confirm the use of this extract as insect control at high concentrations is harmful to plants as non-target organism. It also recommend the use of lower concentration (15%), which has a significant affect on insect with very low side effects on plants. Key words Calotropis procera extract, Cytogenetic effects, Vicia faba The use of synthetic chemicals for plant protection and their cytogenetic effects have been well documented (Shehab 1980, Mohammed 1986, Badr et al. 1985, Qureshi et al. 1988. No doubt, that most of synthetic chemical used surround the world resulted in disturbances of environment and lethal on non target organisms e.g., plant, animal etc. For these reasons, it has become necessary to search alternative natural compounds for environmental safety.Extracts of many plants have been tested for the above reasons (El Gammal et al. 1988, Nassar 1995, Nassar et al. 1997, Soliman and El Sherif 1995, Mohammed 1986. Although many studies were carried on the cytogenetic effects of many plant extracts (Kumar and Kumar 1972, Kabarity and Malallah 1980, Adams and Rashad 1984, Abderrhman 1998, Shapira et al. 1989, Li et al. 1995, Abou El Kheir and Abou El Kheir 1992, Omani et al. 1996, El Khodary 1980, and some others are still in need for such investigation.Extract of Calotropis procera (Family Asclepiadaceae) has been used as botanical insect growth inhibitor by Nassar (1995) and Giridhar et al. (1984). The extract shows effective results as insecticide at certain concentrations.The aim of this study is to investigate the effect of different concentrations (5, 15, 30, 60%) of this extract on percentage of germination, plant growth and cytogenetic of Vicia faba as non target organism. Parameters measured were plant height, percentage of germination, mitotic index, aberrations and mitotic behaviour.