Objective: The objective of the present study was to develop the Thai version of the Impact and Burden of Care Scale for Caregivers of Persons with Schizophrenia and Co-occurring Methamphetamine Use (TIBSCSM) and test its psychometric properties. Methods: This instrument development research subjects were 142 caregivers of persons with schizophrenia and co-occurring methamphetamine use. Sample size adequacy was tested by Kaiser–Meyer–Olkin (KMO), and Bartlett's test of sphericity tested the adequacy of the item correlation matrix. The second-order confirmatory factor analysis (CFA) was used to test the theoretical model. Results The 32-item TIBSCSM showed convergent validity correlations with two quality-of-life measures. Additionally, KMO=0.9, Bartlett’s Test of Sphericity χ2=5248.5, df=496, p<0.001, and internal consistency reliability was high (α=0.9). The CFA has shown that the findings are supported by the theoretical models (χ2=325.2, df=287, p<0.001, RMSEA=0.0, CFI =0.9). Conclusion: The TIBSCSM scale has potential benefits for psychiatric nurses and psychiatric care teams to measure the impact and care burden of caregivers of persons with schizophrenia and methamphetamine use in the areas of nursing, research, education, and clinical determination. The test results suggested that The TIBSCSM scale has potential benefits for psychiatric and mental health care team to assess the impact and burden care of schizophrenic caregiver for both research and clinical purposes, especially during the COVID-19 pandemic for providing care to relieve the impact and burden of care.