Background <p>Existing instruments measuring self-efficacy are generally developed for specific populations or health conditions and may not adequately capture the caregiving challenges faced by caregivers of bedridden patients. Therefore, a valid and reliable scale is needed to assess the self-efficacy levels of caregivers of bedridden patients.</p> Methods <p>This methodological study was conducted with informal caregivers of bedridden patients registered in home health care services in Trabzon and Rize, Türkiye. An initial item pool consisting of 66 items was generated based on the literature. The draft scale was pilot tested with 33 caregivers. Data were collected from 571 caregivers. Exploratory Factor Analysis (EFA) was conducted with 314 participants, and Confirmatory Factor Analysis (CFA) was performed with a different sample of 257 participants. Reliability analyses included Cronbach’s alpha and test–retest analysis.</p> Results <p>The content validity index of the draft Caregiver Self-Efficacy Scale was 0.705. The Kaiser–Meyer–Olkin value for EFA was 0.913 and Bartlett’s test of sphericity was significant (χ² = 5377.750, <i>p</i> &lt; 0.001). Following content validity, exploratory factor analysis and reliability analysis, the number of items was reduced from 51 to 29. The final scale consisted of four factors: caregiving, disease knowledge, stress management, and social support. Confirmatory factor analysis indicated acceptable model fit (RMSEA = 0.07, CFI = 0.90). The Cronbach’s alpha coefficient for the total scale was 0.939.</p> Conclusions <p>The Caregiver Self-Efficacy Scale is a valid and reliable instrument that can be used to assess the self-efficacy levels of caregivers of bedridden patients.</p>