Introduction Foetal alcohol syndrome (FAS) is caused by excessive maternal alcohol use during pregnancy. It is one of the major causes of preventable congenital anomalies and developmental disabilities. 1 It presents with growth retardation, abnormal facial features and brain dysfunction. 2 The full spectrum of prenatal alcohol effects is referred to as Foetal Alcohol Spectrum Disorder (FASD). 3 Drinking has long been the most common type of alcohol intake for centuries. But nowadays another route is getting very popular among the western population, which is inhalation of alcohol vapours rather than drinking. For this purpose a new device, "Alcohol Without Liquid Vaporizer" has been used for inhaling vapours rather than drinking. 4 Companies who are manufacturing the product claim that it will allow consumers to enjoy pleasurable effects of alcohol intake without any harmful effects. But scientists are of the opinion that alcohol intake through this route will lead to direct absorption through the nose and lungs into bloodstream bypassing the stomach and liver. 5 Various animal models have been used by researchers to investigate the causative factors and effects of various alcohol-related diseases. Such models have helped researchers explore the mechanisms by which both short- term and long-term drinking can interfere with normal developmental processes of the embryo. Chick embryo is a popular experimental model to study the effects of ethanol on different developmental processes in an embryo. 6 Humans are also involuntarily exposed to ethanol vapours since ethanol is added to gasoline. Studies are carried out to investigate the neuromotor effects of ethanol vapour exposure on human volunteers. 7 This research was conducted to expose chick embryos to ethanol vapours produced in a specially designed vapour chamber. These chicks were grossly examined to see any developmental defects, along with their hatchability characteristics which included their day and mode of hatching. Materials and Methods The study design of this project was experimental. Chick embryos were exposed to ethanol vapours and compared with controls. The project was carried out at Department of Anatomy, Regional Centre, College of Physician and Surgeon, Islamabad between Febuary 2006 to February 2007. A total of 180 'Desi' ('Desi' is a term used in the South Asian region to refer to poultary animals which are strictly fed an organic vegetarian-alone diet, without any animal or unnatural sources fed to them, thus precluding any artificial effects on the animals from artificial, blended or non-organic feeds) chicken eggs collected from Poultry Research Institute, Punjab, and Rawalpindi were divided into control group A and experimental group B of 90 eggs each. The day when eggs were placed in the incubator was taken as day 1. Each group was further subdivided into 3 subgroups based on the day of sacrifice or hatching. Subgroup 1 was sacrificed at Vol. 61, No. 4, April 2011 328 Original Article Teratogenic effects of Ethanol Vapour exposure on chick embryos Kiran Kamran, 1 Muhammad Yunus Khan, 2 Liaqatali Minhas 3 Department of Anatomy, Foundation University Medical College, 1 Regional Center, College of Physician & Surgeons, 2 Yusra Medical & Dental College, 3 Islamabad. Abstract Objective: To observe the effect of ethanol vapours on chick embryos regarding developmental defects and hatchability characteristics. Methods: An experimental study was performed in the Department of Anatomy at the Regional Center of College of Physicians and Surgeons, Islamabad, from February, 2006 to February, 2007. Chicken eggs after having been exposed to ethanol vapours produced in a specially designed glass chamber, were dissected on day 7, day 10 and day 22 or on hatching and compared with age-matched controls. A breathalyzer was used for monitoring level of ethanol vapours inside the incubator. Results: The results show that experimental group had comparatively more cases of delayed and assisted hatchings as well as growth retardation resulting into failure of retraction of yolk sac, as compared to the controls. Conclusion: Ethanol vapour exposure increases the risks of developmental defects with increasing embryonic age. Increased duration of exposure, causes delayed hatching and more assisted hatchings. Newly hatched alcohol exposed chicks showed diminished locomotor activity and poor balance. Keywords: Chick embryo, Ethanol vapours, Growth retardation (JPMA 61:328; 2011).