The fineness of material for iron ore pelletizing is generally 80% to 90% -325# (45 mum). The presence of oversize particles (+500 mum) in the feed does not exceed a few tenths of a percent and their behaviour in pelletizing has not attracted much attention. This is partly because the behaviour of oversize particles can not be easily observed in lab tests. In a recent industrial plant-scale test, it was determined that oversize particles tend to accumulate in the green balling circuit. Such an occurrence does adversely affect the balling process. The results of the industrial plant-scale investigation on the mentioned subject are presented in this paper.