This extended review critically compares two edited texts which explore institutional and societal responses to the health risks posed by the presence of HIV infection in blood used for medical purposes. The review is used to raise more general issues about cross-national comparisons and regulatory responses to new risks. The texts reviewed are Bovens, 't Hart and Peters (2001) Success and Failure in Public Governance. A Comparative Analysis and Feldman and Bayer (1999) Blood Feuds. AIDS, Blood and the Politics of Medical Disaster. The review draws a number of conclusions from analysis and comparison of these texts. First, ingrained assumptions (in this case, that transfused blood from unpaid donors is inherently safe) may impede responsiveness to new risks. Second, national political responses to adverse events (in this case HIV infection through medical use of blood products) are not directly related to the adequacy of the regulatory response. Third, the two texts come to somewhat different conclusions about the adequacy of the regulatory response to the contaminated blood crisis. This discrepancy is explained in terms of differences in approach to cross-national comparison.