This study was carried out in 2011 and 2012 to determine the host plants, distribution areas and infestation rates of Tomato leaf miner (Tuta absoluta) which causes damage in tomato in the Northeast Anatolia Region. Studies were conducted in Erzincan and Iğdır provinces where in greenhouse and fields, tomato was grown extensively. In the surveys, 30-40 plants were randomly selected and all parts of these plants were investigated with a magnifier. In the event of any biological pre-adult stage or signs of damage of the pest on the plants; that area and plant were recorded as infested. To determine the host plants of tomato leaf miner, surveys were made in greenhouse and open field grown tomato and weeds in the inside and the edges of the tomato plant. It was determined that a large part of Erzincan and Iğdır provinces of Northeast Anatolia Region were infested with tomato leaf miner. The infestation rate of tomato leaf miner was 6.13% in Erzincan, 3.08% in Iğdır in 2011; 3.65% in Erzincan, 9.21% in Iğdır in 2012. It was also determined that in addition to tomato, nightshade (Solanum nigrum) was a host plant of tomato leaf miner.