Background China has 129 dialects with Mandarin as the standard and Chaoshan as the major dialect of the Chaoshan region in Guangdong. This study aimed to describe the dialect competence and usage, communication difficulty, impact of linguistic barriers, and subjective experience in healthcare. Methods Healthcare providers (n = 234) and healthcare consumers (n = 483) at two tertiary teaching hospitals in Shantou, Chaoshan region participated in an anonymous survey. Results Chaoshan and Mandarin were spoken respectively by ca. 80% and 6.1% of the participants. Monolinguals accounted for 28.5%, including 16.8% of Chaoshan-speaking healthcare providers and 18% of Mandarin-speaking healthcare consumers. The monolinguals preferentially used their competent dialect (Ps < 0.001) and had significant communication difficulties (Ps < 0.0001), with the mean (SD) score of 3.06 (0.96) out of 4 with Mandarin for healthcare providers and 2.18 (1.78) and 1.64 (1.40) with Mandarin and Chaoshan, respectively, for healthcare consumers. The monolingual healthcare providers perceived significant negative impacts of linguistic barriers on the entire healthcare delivery process (Ps < 0.0001). Regression analyses showed the length of stay in the Chaoshan region as a protective factor of linguistic barrier with a limited protective effect. Conclusions This is the first report of significant linguistic barriers in healthcare imposed by Mandarin and Chaoshan dialects in Chaoshan, China. With perceived adverse impacts on the entire healthcare delivery and risks to the healthcare quality and burden, interventions such as professional interpreter service, service-learning interpreter program, or mobile interpreting apps that are medically accurate and culturally sensitive are suggested for dialectally diverse China.