Five experiments were conducted on the ways that college students processed ambiguous words in sentences. Two classes of ambiguous words (noun-noun and noun-verb) and two types of context (priming and nonpriming) were investigated using a variable stimulus onset asynchrony (SOA) priming paradigm. Noun-noun ambiguities consisted of two semantically unrelated readings that were nouns (e.g., pen, organ); noun-verb ambiguities had both noun and verb readings that were unrelated (e.g., tire, watch). Priming contexts contained words that were highly related semantically or associatively to one meaning of the ambiguous word; nonpriming contexts favored one meaning of the word through other types of information. In nonpriming contexts, the subjects consistently accessed multiple meanings of words, and selected one reading within 200 msec. Lexical priming differentially affected the processing of subsequent noun-noun and noun-verb ambiguities, yielding selective access of meaning only in the former case. The results suggested that meaning access is an automatic process that is unaffected by knowledge-based (top-down) processing. Whether selective or multiple access of meaning is observed depends largely on the structure of the ambiguous word, not the nature of the context. (Author/RL)