Very little is known about the role of early interactions in the development of peer relationships among toddlers. The present study examined whether behaviors early in the formation of toddler relationships predict interactions later in their relationships. Twenty-eight unfamiliar 20- and 30-month-old toddlers from a predominately European background met separately with each of two other toddlers for 18 playdates. Both positive and negative behaviors at the beginning of the relationship predicted a higher frequency of games later in the relationship. Positive behaviors at the beginning of the relationship predicted fewer conflicts later in the relationship. Negative behaviors at the beginning predicted more conflicts later in the relationship. These findings suggest that toddlers' behaviors, when they initially meet, underlie the pathway in which their relationship develops.