This study aimed to characterize factors that influence early dialect development in a language environment with multiple dialects. Children were evaluated for these dialect effects compared with normal hearing referenced measures of speech and language development that are commonly implemented in hearing-impaired children. Dialect exposure and use were assessed longitudinally in Chinese children (2-6 years old) that were raised in a community where Putonghua (PTH) and Sichuanhua (SCH) Mandarin dialects were used. Lexical tones in these dialects are different. A total of 20 boys and 20 girls (2 years old at the beginning of the study) that attended the same nursery school were included in this study. SCH was used by the majority of subjects <4 years old. The majority of subjects >4 years old used either dialect, with a few users of both dialects at this age. PTH tone perception did not differ significantly as a function of dialect use. Tone recognition and discrimination were >90% accurate by 6 years old, in contrast to previous results for children with minimal exposure and use of PTH. Children with approximately ⩾50% PTH exposure might be accurately assessed with norm-referenced speech materials spoken in PTH, regardless of their preferred dialect. However, the current norm-referenced assessments of children with minimal PTH exposure and nonusers of the dialect might be inaccurate.