An evaluation was made on the effects of an improved staff ratio in New Zealand kindergartens. Aspects of four typical kindergartens staffed by two teachers were compared with aspects of four kindergartens that were provided with a third teacher. Data were collected from teachers, kindergarten children and parents. Findings indicated that the introduction of a third teacher was associated with a statistically significant reduction in children's negative behavior in relation to peers. Children had more positive play with peers, talked more, and interacted more with teachers after the third teacher arrived. After the third teacher was introduced, teacher behavior showed fewer changes than did child behavior, but teachers in the third-teacher kindergartens made more nonverbal initiations to children, talked more to parents, were more involved in children's play, and talked more to each other. Teachers believed that the introduction of a third teacher needed to be accompanied by considerable in-service work on leadership and management, and some findings lent credence to that belief. Adult-child ratios did not improve as much as expected in kindergartens with three teachers. It was concluded that the third teacher was a valuable addition, and that transition support should be provided. (RH)