Aim: To relate visual field function to brain morphology in children with unilateral cerebral palsy (CP). Method: Visual field function was assessed using the confrontation technique and Goldmann perimetry in 29 children (15 males, 14 females; age range 7-17y, median age 11y) with unilateral CP classified at Gross Motor Function Classification System (GMFCS) level I and Manual Ability Classification System levels I to III. The type and extent of brain lesions were determined using cerebral imaging. Results: Eighteen children had subnormal visual field function. The visual fields were severely restricted in six. The underlying brain lesions were malformation (n=7), white matter damage of immaturity (WMDI; n=13), and cortical-subcortical lesions (n=9). Visual field function could be correlated with the pattern of brain damage in children with cortical-subcortical lesions or extensive lesions caused by malformation or WMDI. Total homonymous hemianopia was common in the cortical-subcortical group but rare in children with malformation or WMDI. Five children had normal visual field function despite having malformation or WMDI involving parts of the brain usually encompassing the visual system. Interpretation: Visual field function may be preserved by plasticity of the immature brain in children with malformation and WMDI. Severely restricted visual fields were more often associated with lesions occurring later in the developing brain. All children with severely restricted visual fields were identified by the confrontation technique. Goldmann perimetry was a suitable method to identify relative visual field defects.