The current study explored causal language in 3.5- to 4-year-old children by manipulating the type of agent (human acting intentionally or unintentionally, or inanimate object) and the type of effect (motion or state change) in causal events. Experiment 1 found that the type of agent, but not the type of effect, influenced children's production of causal language. Children produced more causal language for intentionally caused events than for either unintentionally- or object-caused events, independent of the type of effect. Experiment 2, which tested children's judgments of descriptions for the events, found a similar pattern. Children preferred causal descriptions more for the intentionally caused events than the unintentionally- and the object-caused events. Experiment 3 found no evidence of bias in children's non-linguistic representations of the events. Taken together, these results suggest an intention-to-CAUSE bias in children's mapping of conceptual representations of causality into linguistic structure. We discuss the implications of these results for the acquisition of causal language and for the development of conceptual representations of causality.