This pilot study was designed to test the efficacy of adding home-based Developmental, Individual-Difference, Relationship-Based (DIR)/Floortime[TM] intervention to the routine care of preschool children with autistic spectrum disorder. Measures of functional emotional development and symptom severity were taken. It was found that after the parents added home-based DIR/Floortime[TM] intervention at an average of 15.2 hours/week for three months, the intervention group made significantly greater gains in all three measures employed in the study: Functional Emotional Assessment Scale (FEAS) (F = 5.1, p = 0.031), Childhood Autism Rating Scale (F = 2.1, p = 0.002), and the Functional Emotional Questionnaires (F = 6.8, p = 0.006). This study confirms the positive results obtained by a previous DIR pilot study (Solomon et al., 2007). (Contains 2 tables.)