Skin diseases are a major public health concern in Indonesia, although access to specialized care in remote areas is limited. We initiated a low-cost teledermatology service in Sumba, a remote island in eastern Indonesia. Eighteen healthcare workers (HCWs) at five primary healthcare centers received training to manage common skin diseases and submit clinical cases beyond their expertise to an online platform. Submitted cases were reviewed by at least one dermatologist. Diagnostic agreement between HCWs and dermatologists was calculated. The HCWs participated in a satisfaction survey 2 years after project initiation. Since October 2020, of 10,384 patients presenting with skin complaints in a 24-month period, 307 (3%) were submitted for a teledermatology consultation. The most frequent skin diseases were infections and infestations (n = 162, 52.8%) and eczematous (85, 27.7%) and inflammatory (17, 5.5%) conditions. Fifty-three patients (17.3%) were diagnosed with a neglected tropical skin disease, including leprosy and scabies. Dermatologist advice was provided within a median of 50 minutes (interquartile range, 18-255 minutes), with 91.9% of consultations occurring within 24 hours. The diagnostic agreement level between HCWs and dermatologists significantly improved over time, from 46.9% in the first 6-month period (κ = 0.45; 95% CI, 0.37-0.54) to 77.2% in the last 6-month period (κ = 0.76; 95% CI, 0.67-0.86; global P < 0.001). The HCWs reported that the teledermatology service was extremely/very useful in supporting daily practice (100%) and improved their knowledge of skin diseases tremendously/a lot (92%). Teledermatology can improve accessibility and quality of skin services in medically underserved areas, providing opportunities for scalability and knowledge transfer to frontline HCWs.