Strategies that promote the development of language skills are recognized as important in early childhood education. For early childhood centers and care providers, there are also additional concerns that interventions which meet these developmental needs are both time and cost effective. This pilot study investigates the effect of indirect language stimulation (ILS) techniques on the receptive and expressive oral language of 4-year-olds, using techniques that can be easily taught to teachers and implemented in the classroom. Two preschool teachers in a southwest rural community in the United States were randomly assigned for instruction over a 6-month period on effective ways of integrating ILS techniques into their regular classroom instruction. Students were assessed with the PPVT-4 (receptive language) and the EVT-2 (expressive language) to determine the effect these techniques had on their English language vocabulary. Results indicate that students in classrooms where teachers received the professional development (n = 31) had significantly higher growth in expressive language scores (p = .012) than students in comparison classrooms (n = 34). This study suggests that a low-cost 2-day training intervention can be beneficial for preschool teachers and their 4-year-old students' language acquisition. (author abstract)