There is not enough evidence regarding the effects of trunk control on respiratory muscle strength and activities of daily living (ADL) in children with cerebral palsy (CP). This study was planned to investigate the effects of trunk control on respiratory muscle strength and ADL in children with spastic CP. A total of 34 children with spastic CP (M +/- SD age, 9.3 +/- 2.4 years) and 30 typical peers (M +/- SD age, 9.7 +/- 2.1 years) were included in the study. Trunk control was evaluated by the Trunk Control Measurement Scale (TCMS), ADL was evaluated by Pediatric Evaluation of Disability Inventory (PEDI), and respiratory muscle strength was evaluated by mouth pressure meter. The trunk control, respiratory muscle strength, and ADL of the children with spastic CP were significantly lower than their typically peers (P < 0.001, respectively). There were statistically significant correlations between the trunk control and maximum inspiratory pressure (MIP) (r= 0.503, P < 0.05), maximum expiratory pressure (MEP) (r = 0.465, P < 0.05), mobility subscale of Functional Skills Scale of PEDI (FSS-MS) (r = 0.570, P < 0.001), self-care subscale of Caregiver Assistance Scale of PEDI (CAS-SS) (r= 0.431, P < 0.05), mobility subscale of Caregiver Assistance Scale of PEDI (CAS-MS) (r = .607, P < 0.001), and Gross Motor Functional Classification System (GMFCS) (r = -0.522, P < 0.05) in children with spastic CP. In addition, MIP, MEP, PEDI FSS-MS, CAS-SS, and CAS-MS were independently predictors of trunk control in children with spastic CP. The results of this study demonstrate that trunk control in children with spastic CP is correlated positively to MIP, MEP values and their daily living activities and we suggest this should be taken into account when planning an intervention to improve the ability of daily living function for children with spastic CP.