Impression making is an art. An accurate impression is the backbone of prosthodontics. Making acceptable final impressions when fabricating complete dentures is an important requirement for the successful treatment of edentulous patient as the secondary impression will be incorporated in the final denture as intaglio surface of the denture. Thus, any flaw if occurred during this step will be reproduced in the final denture which will directly affect the prognosis of the denture. In this book, various techniques and materials used for secondary impression have been elaborated.