Background: Vocabulary skills in infants with cleft lip and/or palate (CL/P) are related to various factors. They remain underexplored among Mandarin-speaking infants with CL/P. This study identified receptive and expressive vocabulary skills among Mandarin-speaking infants with unrepaired CL/P prior to cleft palate surgery and their associated factors. Methods: This is a cross-sectional study involving patients at the Cleft Lip and Palate Center of the Stomatological Hospital of Xi’an Jiaotong University between July 2017 and December 2018. The Putonghua Communicative Development Inventories-Short Form (PCDI-SF) was used to assess early vocabulary skills. Results: A total of 134 children aged 9-16 months prior to cleft palate surgery were included in the study. The prevalences of delays in receptive and expressive vocabulary skills were 72.39% (95% CI: 64.00-79.76%) and 85.07% (95% CI: 77.89-90.64%), respectively. Multiple logistic regression identified that children aged 11-13 months (OR = 6.46, 95% CI: 1.76-23.76) and 14-16 months (OR = 24.32, 95% CI: 3.86-153.05), and those with hard/soft cleft palate and soft cleft palate (HSCP/SCP) (OR = 5.63, 95% CI: 1.02-31.01) were more likely to be delayed in receptive vocabulary skills. Conclusions: Delays in vocabulary skills were common among Mandarin-speaking CL/P infants, and age was positively associated with impaired and lagging vocabulary skills. The findings suggest the necessity and importance of early and effective identification of CL/P, and early intervention programs and effective treatment are recommended for Chinese CL/P infants.