Assigning stress to polysyllabic words is a crucial aspect of reading aloud in English. Previous research demonstrated that native English speakers are sensitive to word endings as probabilistic orthographic cues to stress assignment. However, little is known about if second language (L2) learners of English are sensitive to word endings as cues to lexical stress. The current study investigated whether native Chinese-speakers learning English as a second language (ESL) are sensitive to word endings as probabilistic orthographic cues to lexical stress. Our ESL learners demonstrated sensitivity to word endings as cues in a stress-assignment task and a naming task. With the increase in language proficiency, ESL learners responded more accurately in the stress-assignment task. Moreover, stress position and language proficiency moderated the strength of the sensitivity, with a trochaic bias and better proficiency leading to better sensitivity in the stress-assignment task. However, as language proficiency increased, participants' naming speed became faster in iambic but slower in trochaic patterns, reflecting the learners' fledgling knowledge about the specific stress patterns associated with varying orthographic cues, especially in a demanding naming task. Taken together, the evidence from our ESL learners fits in the proposed statistical learning mechanism, that is, L2 learners are able to implicitly extract statistical regularities from linguistic materials, the orthographic cues to lexical stress in our study. Stress position and language proficiency both play a role in developing this sensitivity.