Ethno-STEAM is a combination of ethnosciences and STEAM. This research aims to describe Ethno-STEAM learning related to the traditional Kacaping musical instrument and to examine its influence on improving students’ problem-solving skills and motivation to preserve local wisdom. This study employs a quantitative approach, a quasi-experimental design, and a pretest-posttest control group design. The research consists of two classes: an experimental class receiving Ethno-STEAM treatment and a control class receiving conventional learning, each with 30 participants. Instruments used in this study include a Learning Implementation Questionnaire to assess the implementation of Ethno-STEAM learning, an essay test to assess participants’ problem-solving skills, and a non-test instrument to measure motivation to preserve local wisdom. The research results indicate that the implementation of Ethno-STEAM in relation to the traditional Kacaping instrument achieves an 81.25% rate, interpreted as “good.” The Independent Samples t-test showed a significant difference in problem-solving skill improvement between the classes (p < 0.05), with a large effect size (Cohen's d = 1.64). Regarding the increase in motivation to preserve local wisdom, the Independent Samples t-test indicates a significant difference between the experimental and control classes (p < 0.05), with a Cohen's d of 0.70 (medium). Ethno-STEAM related to the traditional Kacaping instrument can enhance participants’ problem-solving skills and motivation to preserve local wisdom, compared to conventional learning.