This study investigated the effect of science experiences on the fifth-grade Trinidadian child's concept of Piagetian physical causality. The sample comprised 835 children from 37 schools. The tests used were the Concept Assessment Kit—Conservation Forms A & B, the Metropolitan Achievement Test, Form C, and two clinical interviews which assessed the child's concepts of living and floating. The experimental group scored significantly higher than the control group. Experimental group girls scored significantly higher than Experimental group boys for the concept of living; no significant difference was found between boys and girls for the concept of floating. A high correlation was found between scores on verbal ability and clinical interviews. A change in developmental level did not affect the child's ability to understand the concepts taught. The study concluded that participation in the selected science experiences tended to accelerate or enhance the understanding of the concepts of living and floating.