Class of 2006 Abstract / Objectives: To examine the influence stock market crashes have on pharmaceutical security prices. More specifically, the objectives are to quantify the stock market abnormal returns and volatility of domestically listed drug companies during periods of stock market crashes. Methods: An event study methodology was performed to determine the impact of stock market crashes on security prices of pharmaceutical firms. Pharmaceutical security price data was obtained from the Center for Research in Securities Prices (CRSP) database. Stock market crashes were identified and economic considerations regarding the nature of security price returns were reviewed including normality, autocorrelation, heteroscedasticity and cross sectional dependence. Results: The estimation period for the study ranged over a period of thirty-five months (-45 to -5) prior to the stock market crash. Mean estimates of the SIMM mean beta parameter ranged from 0.51-1.18 for all companies analyzed within the period of 1929-2001. Mean monthly abnormal returns ranged from 0.0039-0.0348 during the estimation period. Over a period of one, three, and five months the majority of the pharmaceutical industry failed to consistently produce above average abnormal returns. Conclusions: The purpose of this study was to investigate the performance of the pharmaceutical industry during ten stock market crashes to verify and or quantify current literature statements about the recession proof nature of the drug sector. The current investigation found that during the estimation periods surrounding the stock market crashes, the pharmaceutical industry did not outperform the average market return.