The present paper proposes to measure the ‘‘functional load of pitch-accent’’ for Japanese words. It is calculated from (1) the ratio of the number of accentually contrastive homophone pairs to the number of noncontrastive pairs; and (2) the difference between word-familiarity ratings for each pair. The functional load is larger when there are more contrastive homophones to noncontrastive homophones for the target word, and when the difference of word familiarity scores is smaller between each homophone pair. A large scale word-familiarity database is used for the calculation of functional load and other statistical properties of pitch accent. Distribution of accent and opposition types at each word length are investigated with respect to familiarity scores. Results show that oppositions which include an unaccented form dominate in short simplex words, from low to high-familiarity range. This suggests that the role of pitch accent in distinguishing homophones is biased to the presence–absence contrast, and not to the location per se of pitch accent. Preliminary results from a perception experiment suggest that top-down information in the lexicon, such as functional load and distribution of accent and opposition types, interacts with the bottom-up process in lexical access.