Erythema nodosum[EN] is a common form of panniculitis and inflammatory disease of the subcutaneous fat tissue.EN occurs in a variety of disorders including tuberculosis, sarcoidosis, Behcebs disease, inflammatory bowel disease and streptococcal infection but idiopathic cases account for 55%. A 14 years old patient was diagnosed as Erythema nodosurn[EN] with prolonged fever and red subcutaneous nodules in pretibial location. With tuberculin skin and Quantiferon positivity and tree in bud sign in chest x ray she was diagnosed as tuberculosis. On the same dates a 11 years old patient was admitted with EN. She was also diagnosed as tuberculosis due to tuberculin skin and Quantiferon positivity and hilar lymphadenopathy in thorax CT. The other causes were excluded in both cases. We present these two adolescents cases to keep in mind the close relationship between tuberculosis and erythema nodosum.