Mental imagery is a foundational human faculty that depends on active image construction and sensorimotor experiences. However, children now spend a significant proportion of their day engaged with screen-media, which (a) provide them with ready-made mental images, and (b) constitute a sensory narrowing whereby input is typically focused on the visual and auditory modalities. Accordingly, we test the idea that screen-time influences the development of children's mental imagery with a focus on mental image generation and inspection from the visual and haptic domains. In a longitudinal cross-lagged panel design, children (n = 266) aged between 3 and 9 years were tested at two points in time, 10 months apart. Measures of screen-time and mental imagery were employed, alongside a host of control variables including working memory, vocabulary, demographics, device ownership, and age of exposure to screen-media. Findings indicate a statistically significant path from screen-time at time 1 to mental imagery at time 2, above and beyond the influence of the control variables. These unique findings are discussed in terms of the influence of screen-time on mental imagery.