Researchers suggest that monolingual children with clefts of the lip and/or palate (CL/P) that are not attributable to genetic syndromes are at risk of poor communication outcomes. The role of bilingualism in language acquisition in infants and toddlers with CL/P has received little attention. In a prospective longitudinal study, six English-Mandarin toddlers with CL/P aged 11-16 months were compared with six age-matched typically developing (TD) peers on the size of their receptive and expressive vocabularies and the age of their first word. They were also case-matched pair-wise on language dominance, sex, and socioeconomic status. The Singapore Communicative Development Inventories for English and Mandarin were used to measure vocabulary size via parental report. Growth in vocabulary was compared after a four-month interval. Results revealed that toddlers with CL/P had smaller expressive vocabularies than TD peers at baseline, but their vocabularies did not significantly differ from TD peers four months later. Receptive vocabulary size was larger for toddlers with CL/P than TD peers at both time points. Age of first words did not differ between groups. As such, toddlers with CL/P were not observed to have smaller receptive vocabularies than TD peers, and they appeared to subsequently catch up with TD peers in terms of expressive vocabulary. Findings thus suggest that toddlers with CL/P with no or low additional risk factors may not require direct language intervention by a speech-language pathologist, but home language stimulation and monitoring of vocabulary development may still be important and desirable. Future work with a larger sample is recommended.