This study compares the textual complexity of periodic and nonearnings/unscheduled disclosures and identifies whether they have different determinants. Evidence shows that nonearnings disclosures are textually less complex than periodic disclosures, though both disclosures become less readable, lengthy and boilerplate over the sample period. Further, firms from the resource, finance, and regulated industries tend to produce more textually complex periodic disclosures than nonearnings due to their complex structure and business practices. In terms of determinants, compared to periodic disclosures, the textual complexity of nonearnings disclosures is more influenced by time trends, market-to-book ratio, special items, and gearing, but not by poor performance. Besides firm-specific factors, the textual complexity of nonearnings disclosure is also influenced by managers' strategic reporting, mainly when bad news is released after trading hours or on the week's last trading day.