Relevant literature has an unexplored question on how prediction-observation-explanation (POE) worksheets affect science process skills of students with mild intellectual disabilities (SMID). Therefore, this research aimed to examine the effect of POE worksheets developed for the "matter and its nature" subject on SMID's science process skills. Through pre-experimental research design, 12 fifth grade SMID participated in the research. To collect data, the researchers used science process skills development forms and rubrics to score their observations. During the teaching intervention, SMID implemented three POE worksheets, which included buzz 22 technique in the 'prediction' stage, hands-on experiments and QR codes in the 'observation' stage and snowball, learning gallery or card showing techniques in the 'evaluation' stage. The results indicated that the POE worksheets are effective at developing SMID's science process skills of the "matter and its nature" subject. This research recommends that future comparative research should unveil how the POE worksheets with/without active learning techniques impact the SMID's SPS.