The survey on modern chicken farms which include two important industries: raising broiler chickens and raising layer chickens was conducted in the year 1391[1]. In this Survey, the last available list of national chicken farms in Iran which was prepared in the year 1388 for broiler chicken farms and in the year 1390 for the laying chicken farms was used.  For this Survey 8365 man/ day enumerators, 1694 man/ day checkers, 2091 man/ day executive group leaders, 775 man/day experts, and 4182 man/day cars with driver were used. The Offices of General Governors in all provinces were in charge of carrying out the Survey in their provinces. This Survey started on 3 Tir 1391[2] and finished on 26 Tir 1391[3].  The designed software was used to extract and disseminate the results of this Survey in a decentralized way.
 
 In line with its duty to produce the basic information and statistics and in order to meet the statistical needs of the users, the Statistical Centre of Iran (SCI) began The Survey on the Layer Chicken Farms in the year 1364 and continued it  for the years  1370,1373, 1375, 1378, 1380, 1382, 1385,1388 and 1390.
 
Chickens raising in a modern way in Iran started through importing one-day-old chickens or fertile eggs from breeding chickens in the year 1333.  This industry has been so developed that today it produces significant portion of national animal protein. At the present time different units of chicken farms are developed in different parts in the country.
 
 Poultry raising industry in Iran includes six main activities as: rearing great grandparents stock, grandparents stock; parents stock; production of one-day-old chickens, layer chicken, broiler chicken, and poultry (which is considered as a side activity). Obtaining information on the activity of the layer chicken farms is very important because the final and main product of these farms is egg which, as an important protein and nutritional food, plays an important role in supplying certain animal protein required in the country. 
 
This survey provides the researchers and planners with the information and statistics on the number of layer chicken farms, activity status, hall status, capacity, legal status, the status of layer chicken flock, quantity and quality of products, quantity and quality of consumed hen feed, and the number of employed persons. 
 
Survey History:
 
 With respect to the importance of statistics and information in planning the SCI conducted this survey in the years 1364, 1370, 1373, 1375, 1378, 1380, 1382, 1385, 1388 and 1390 and disseminated their results.