This study compares the disclosures about derivatives and market risk made by 25 SEC registrants in the years before (1996) and after (1997) the adoption of Financial Reporting Release No. 48 (SEC 1997) (FRR No. 48). FRR No. 48 requires firms to disclose how they account for derivatives and provide quantitative and qualitative disclosures about exposure to market risk. Market risk disclosures, encouraged but not required under FAS No. 119, improved greatly under FRR No. 48 but varied widely in detail and clarity. The majority of registrants provided quantitative and qualitative disclosures of market risk; however, only about half of these firms discussed the details and limitations of their risk measurement models and disclosures. Further, certain required or strongly recommended contextual disclosures were almost completely absent. Firms appear to prefer relatively complicated but more discreet disclosure formats to simpler but more revealing disclosure formats. Overall, while registrants greatly increased their disclosures about market risk, the disclosures leave room for improvement in future filings. These findings have significance for disclosure choice in general and the adoption of FAS No. 133 in particular.