A first-line screening instrument, the Preschool Inventory of Trauma Symptoms (PITS), was developed to assess trauma symptoms with a diverse sample of 150 toddlers and preschoolers ( M = 2.49 years; SD = 1.12). Items reflected the current trauma literature, assessment measures, and diagnostic criteria for very young children. A principal component analysis produced a 34-item, four-factor model: Arousal and Hyper-Reactivity, Fearful Attachment, Intrusion and Re-Experiencing, and Avoidance and Negative Cognition and Mood. One validity scale, Response Style, was also developed. All scales significantly correlated ( r = .45 to .81; p < .01) with preestablished trauma measures and demonstrated adequate internal consistency (α = .68 − .87). A receiver operating characteristics curve analysis identified a cut-score with good discrimination ability (.88), sensitivity (.81), and specificity (.81). In a preliminary pilot study, PITS also was found to be sensitive to trauma symptom change following participation in an evidence-based trauma informed treatment program. A copy of the PITS is included in the Appendix for free use by qualified professionals.