The metacognitive performance of four groups of students was examined. The students' processes of visual analysis and discrimination of real-life pictures were used to measure metacognition. There were 61 participants: 18 hearing students, 18 deaf and hard of hearing students, 16 students with mild mental disabilities, and 9 students with physical disabilities. Analysis revealed no significant differences among hearing students, deaf and hard of hearing students, and students with physical disabilities. The performance of these three groups of students was significantly better than the performance of students with mild mental disabilities. It appears that students with mild mental disabilities encountered difficulties with pictures that required complex visual analyses and discriminations. These difficulties were manifested in a form of deficient simultaneous visual processing along with a low level of knowledge acquisition. (Contains 1 table.)