We examine the relation between pre-seasoned equity offering (SEO) announcement date misvaluation and long-run post-SEO performance for a large sample of Australian SEOs made between 1993 and 2001. Our study is motivated by inconsistent findings across countries with respect to the SEO long-run underperformance anomaly first documented in the USA, inconclusive findings with respect to the hypothesis that managers exploit market misvaluation when timing equity issues, and a recent Australian Stock Exchange proposal to loosen SEO regulation. We find SEO firms underperform common share market benchmarks for up to 5 years after the announcement. Using a residual income valuation method, we show that this underperformance is related to pre-announcement date misvaluation. An unexpected result is that underperformance and misvaluation are more severe for private placements than rights issues. Institutional factors unique to the Australian setting, particularly the large number of smaller loss-making firms among private placement issuers, appear to explain the poorer performance of placement firms. Our results are robust to various measurement methods and assumptions, and demonstrate the importance of researching SEO performance in alternative institutional settings.