This article presents a visualization study on nonisothermal bubble growth and collapse in the foam injection molding process (FIM). Observation study can give more insight to the bubble growth in foaming process, especially in the challenging injection foaming process. In this study, besides the growth of bubbles, collapse of the bubbles was also observed which could provide knowledge to the final foam morphology. Cell growth vs. time was recorded and analyzed using a software-equipped high speed camera. To investigate the cell collapse, various holding pressure was exerted on the gas-charged molten polymer. The amount of holding pressure had noticeable effect on the rate of bubble collapse. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 116: 3346-3355, 2010