This study modeled the associations between extrinsic demographic factors and children's speech acquisition in Hong Kong Cantonese. The speech of 937 Cantonese-speaking children aged 2; 4 to 6; 7 in Hong Kong was assessed using a standardized speech test. Demographic information regarding household income, paternal education, maternal education, presence of siblings and having a domestic helper as the main caregiver was collected via parent questionnaires. After controlling for age and sex, higher maternal education and higher household income were significantly associated with better speech skills; however, these variables explained a negligible amount of variance. Paternal education, number of siblings and having a foreign domestic helper did not associate with a child's speech acquisition. Extrinsic factors only exerted minimal influence on children's speech acquisition. A large amount of unexplained variance in speech ability still warrants further research. [Copyright of Clinical Linguistics & Phonetics is the property of Informa Healthcare. Full article may be available at the publisher's website: http://dx.doi.org/10.3109/02699206.2013.763385]