The present study addresses development of an instrument assessing primary school children's procedural knowledge of recycling. It was designed as survey research. The research sample included 361 primary school children whose ages vary from 7 to 10 years so it was decided to make a draft of the instrument with images and drawings of recyclable and non-recyclable materials. Data were analyzed with item-total correlation, comparison of upper and lower 27% groups, inter-item correlation and internal consistency. The results of the study indicate that the RAI is a reliable and valid instrument to assess the procedural knowledge levels of primary school children.