Lab assistant from assistant forum STMIK AMIKOM Yogyakarta is active student who selected from couple step recruitment like administratif selection, writing selection, communication and microteaching. On the selection lab assistant who pass the test, manually selected from Forum Assistant or Lecture. That's why the selection step still have weakness, there are subjective, doesn't have standaritation and hard to decide who can pass if they are have almost same competency. Decision support system for selection lab assistant in this riset using simple additive weighting method. This application will create alternative ranking for lab assistant from the highest score that's selected for the best solution. There are nine criteria used in this method : courses score, semester, recomendation, GPA, how many be an assistant, assistant in the same courses, academic test score, communication test score and microteaching score. Systm build using programing language PHP and MySQL. Testing using training data and testing data that have 90% accuracy of system. With this decision support system hopefully can help lecture and assistant forum to select lab assistant.