This study examines the relationship between German second language (L2) learners' awareness of the German lexical stress assignment system and their ability to accurately assign stress to cognate words with predictable lexical stress. Participants were 31 adult L2 German learners from three groups: native English speakers with a range of German proficiency levels (N = 10), native French speakers with intermediate German proficiency (N = 10), and native French speakers with advanced German proficiency (N = 11). They produced target items in a carrier phrase and then indicated both which syllable they stressed and where stress is supposed to fall. Finally, they provided a rule for assigning stress to each word. Stress production accuracy was similar across the groups, regardless of L1 or L2 proficiency. Participants' ability to verbalize where they had placed stress was a significant predictor of stress assignment accuracy. They produced relatively few rules overall, and the rules they produced were mostly inaccurate. The results point to the greater importance of self-assessment over the ability to produce discrete rules in accurate lexical stress assignment.