Thisstudy investigatedthe effectofmotivational factors on English achievementinanintensiveEnglish course.Theparticipantsconsisted of 164Iranian male militarystaff,agedfrom20to 30.Theparticipants filledatranslatedand adapted version of themini-Attitude Motivation Test Battery (α=.70). Factor analysis of thequestionnaireyielded four principalvariables namely,motivation, integrativeness, organizational influence,a nd anxiety. Descriptive statistics indicatedt hatt he militarystaff were highly motivatedinlearningEnglish andhad lowEnglish learningAnxiety.Italsosuggested that themilitaryorganization wasnot so much supportive in learners'studying English.Furthermore,pathanalysisindicatedthatintegrativeness predictedthe motivation to learnEnglish positively, andthatmotivation wasapositivepredictor of English achievement, whereasorganizational influence wasanegativepredictor of English achievement. Thisstudy confirmedthatmotivation is the single most influential factor of language learningachievement,all other thingsbeing equal. The wider concludingargumentofthispaper is that motivation andits constructs arecontext dependentand therefore, anylanguagelearningcontext hasits ownuniquemotivational model. Finally, basedonthe contextoflanguagelearningapathanalyticmodel of L2 motivation wasproposed.