The aim of this study was to investigate the therapeutic effect of doramectin applied once in an optimum dose on stomach-intestine nematodes on goats naturally infected with gastrointestinal nematodes. Alto to study the effect of the doramectin application on the clinically important biochemical parameters, electrolytes, minerals, vitamin B-12 levels and enzyme activities of goats were affected or not after anthelmentic drug application. For this purpose, the stools in 45 goals between 1-3 year were chosen in Van province and subjected to Fulleborn saturated salt solution method. Thirty goats with gastrointestinal nematodes constituted treatment group and they were doramectin applied (group I). Other 15 goats with gastrointestinal nematodes chose as control group (group II) was not Doramectine applied. Taking stool samples goats with Doramectin treatment and from control group on the 0, 7 and 14 days of application in gram stools, the number of eggs (EPG) were analyzed by modified McMaster method and treatment efficiency was a investigated. After coprocultures, goats were determined to be infected with Trichostrongylus sp., Nematodirus sp., Ostertagia sp., Marshallagia sp., Haemonchus sp. and Oesphagostomum sp. The results demonstrated that Fe, Albumin and hemoglobin levels statistically increased in treatment group in comparison with control group (p<0.05); a significant change in IBP, Ferritin, ALT, AST, total protein, P, Ca, Na and K levels was not observed and minor increases along with the treatment related to time in vitamine B-12, ALP and Mg levels occurred. It was concluded that in goats, one dose of 0.2 mg kg(-1) of subcutaneous doramectin was efficient 100% and no side-effect was observed.