The present technique relates to an image processing device and method which can suppress an increase in an operation time. The image processing device has: an encoding control unit which, upon encoding independently performed per slice for dividing a picture into a plurality of pictures, controls whether or not to adopt for motion information a merge mode of merging a relevant region of an operation target with a surrounding region positioned in a surrounding of the relevant region, based on information of surrounding regions which belong to a relevant slice to which the relevant region belongs; and an encoding unit which encodes the relevant region in the merge mode or a mode other than the merge mode under control of the encoding control unit. The present disclosure is applicable to the image processing device.