In my professional career as a pharmaceutical scientist, I have been involved with severalaspectsofthe drugdevelopmentprocessfrompre-INDto commercialization and, somehow, I usually found myself coming back to a stability-related issue. The stability area seemed to draw my utmost interest because in my day-to-day work, my opportunities involved more than one product, and none of the issues were the same.Eachsituationposedchallengesthatusuallyrequiredanexerciseofjudgment, an understandingof regulations,a knowledgeof science, a graspof compliance,and an appreciation of common practices. Sinceearly2000,Ihavealsobeeninvolvedwithseveraltrainingopportunitiesand I struggled to ?nd good, concise, practical resources, one of which I could just hand to a new scientist who wishes to gain a greater understanding of stability sciences. In addition, I encountered the same questions posted over and over on different stability best practices discussion forums. As a book lover, I also have a good collection of technical books. Unfor- nately, most of the stability related volumes are outdated. Many of these materials are theoretical and do not contain much practical information.I understand that the pharmaceutical industry during this period is quite volatile, and guidelines are changingrapidlywhileregulatoryagenciesareworkingcloselywiththepharmac- tical industryto accommodatethese changes;however,thefundamentalinformation continues to remain quite the same, just as current Good Manufacturing Practices (cGMP) continue to be the standard industry practice. Therefore, I hoped to ass- ble a practical handbook to ?ll this void.