Immunisation is a very important aspect of child health. Invasive pneumococcal and influenza diseases have been major vaccine-available communicable diseases. We surveyed demographics and attitudes of parents of primary school students who received pneumococcal conjugate vaccination (PCV) and compared them with those who did not receive pneumococcal vaccination. The survey was carried out in randomly selected primary schools in Hong Kong. Questionnaires were sent to nine primary schools between June and September 2014. Parents of 3,485 children were surveyed, and 3,479 (1,452 PCV immunised, 2,027 un-immunised) valid questionnaires were obtained. Demographic data were generally different between the two groups. PCV-immunised children were more likely to be female (57.0 vs. 52.2%, P=0.005), born in Hong Kong (94.2 vs. 92.3%, P=0.031), have a parent with tertiary education (49.2 vs. 31.8, P<0.0005), from the higher-income group (P=0.005), have suffered upper respiratory infections, pneumonia, otitis media or sinusitis (P=0.019), and have doctor visits in preceding 12 months (P=0.009). They were more likely to have received additional immunisations outside the Hong Kong Childhood Immunization Programme (64.0 vs. 30.6%, P<0.0005) at private practitioner clinics (91.1 vs. 83.5%, P<0.0005). Un-immunised children were more likely to live with senior relatives who had not received PCV. Their parents were less likely to be aware of public education programme on PCV and influenza immunisation, and children were less likely to have received influenza vaccination. The major reasons for PCV immunisations were parent awareness that pneumococcal disease could be severe and vaccines were efficacious in prevention. The major reasons for children not being immunised with PCV were concerns about vaccine side effects, cost, vaccine not efficacious or no recommendation by family doctor or government. In conclusion, PCV unimmunized children were prevalent during the study period. Reportedly, they were generally less likely to have received influenza and other childhood vaccines, and more likely to live with senior relatives who had not received PCV and influenza. These observations provide important demographic data for public health policy in childhood immunisation programme.