This study was conducted to determine the infestation rate of broomrape (Orobanche ramose) and population density of its natural enemy Phytomyza orobanchia (Diptera: Agromyzidae) in tomato production areas of Canakkale province, in 2013-2014 years. It is determined that 58% of tomato production areas of Canakkale is infested with broomrape and P. orobanchia was acquired from 1-13,6% of this areas. The relationship between broomrape plant density and P. orobanchia was investigated in 10 different tomato parcels with different tomato cultivars. It is determined that, broomrape plants were observed after July 4th and P. orobanchia were acquired from plant samples after August 15th. Adult emergence has continued throughout September, until the end of harvest season. The highest number of P. orobanchia adults was observed from Rio Grande cultivar, which was sowed in May 25th.