Mental imagery is a cognitive ability that enables individuals to simulate sensory experiences without external stimuli. This complex process involves generating, manipulating, and experiencing sensory perceptions. Despite longstanding interest, understanding its relationship with other cognitive functions and emotions remains limited. This narrative review aims to address this gap by exploring mental imagery’s associations with cognitive and emotional processes. It emphasizes the significant role of mental imagery on different cognitive functions, with a particular focus on learning processes in different contexts, such as school career, motor skill acquisition, and rehabilitation. Moreover, it delves into the intricate connection between mental imagery and emotions, highlighting its implications in psychopathology and therapeutic interventions. The review also proposes a comprehensive psychometric protocol to assess mental imagery’s cognitive and emotional dimensions, enabling a thorough evaluation of this complex construct. Through a holistic understanding of mental imagery, integrating cognitive and emotional aspects, researchers can advance comprehension and application in both research and clinical settings.