Background: Patients with dementia often present agitated behaviors. The Cohen–Mansfield Agitation Inventory-short form (CMAI-SF) is one of the most widely used instruments to evaluate agitated behaviors that affect patients’ quality of life and impose burden on caregivers. However, there is no simplified Chinese version of the CMAI-SF (C-CMAI-SF) in clinical settings. Purpose: This study aimed to develop a Chinese version of the C-CMAI-SF and examine its validity and reliability. Methods: This cross-sectional study included three phases. In Phase I, the original CMAI-SF was translated to Chinese. In Phase II, experts were invited to examine the content validity index (CVI). Phase III was conducted to test the validity and reliability of the C-CMAI-SF. Results: The scale showed good validity and reliability with a scale-level CVI of 0.89, Cronbach’s alpha (measure of internal consistency) of 0.874, and test–retest correlation coefficient of 0.902 (for 257 individuals). Using factor analysis, three factors were identified. Regarding concurrent validity, the C-CMAI-SF score was correlated with the Neuropsychiatric Inventory (agitation aggression subscale) and the Cornell Scale for Depression in Dementia (agitation subscale). Conclusions: The study demonstrated that the C-CMAI-SF is a valid and reliable instrument for evaluating agitated behaviors in people with dementia. Relevance to clinical practice: The C-CMAI-SF is an easy and quick tool used to identify and evaluate agitated behaviors in busy clinical settings.