This report describes the development and psychometric properties of the Children's Florida Obsessive Compulsive Inventory (C-FOCI). Designed specifically as a brief measure for assessing obsessive-compulsive symptoms, the C-FOCI was created for use in both clinical and community settings. Study 1 included 82 children and adolescents diagnosed with primary Obsessive-Compulsive Disorder, and their parents. The Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS) was administered to assess symptom severity. Thereafter, parents completed the Child Obsessive-Compulsive Impact Scale--Parent Version and Child Behavior Checklist, and youth completed the C-FOCI, Child Obsessive-Compulsive Impact Scale--Child Version, Multidimensional Anxiety Scale for Children, and Children's Depression Inventory--Short Form. A subgroup of 21 individuals was retested with the C-FOCI after completing 14 sessions of intensive cognitive-behavioral therapy. Construct validity of the C-FOCI was supported vis-a-vis evidence of treatment sensitivity, and moderate relations with clinician-rated symptom severity, the CY-BOCS Symptom Checklist, child- and parent-rated functional impairment, child-rated anxiety, and parent-rated internalizing symptoms. Discriminant validity was evidenced by weak relationships with parent-reports of externalizing symptoms. For Study 2, 191 non-clinical adolescents completed the C-FOCI to assess the feasibility of internet administration. Overall, internal consistency was acceptable for the C-FOCI Symptom Checklist and Severity Scale, and respondents were able to complete the measure with little difficulty. Taken together, the findings of Studies 1 and 2 provide initial support for the reliability and validity of the C-FOCI for the assessment of pediatric obsessive-compulsive symptoms.