Inhibition constitutes one of the main executive functions and it is important to more complex skills such as fluid intelligence. Actually, there is an agreement on distinguishing three inhibitory types: perceptual, cognitive and response inhibition. Several studies show the differential engagement of these inhibitory types in different skills. However, there is no registered evidence about the differential relation of inhibitory types with fluid intelligence. This inquiry is especially important during the first school years, since in this stage, inhibitory processes would already be differentiated, and inhibitory processes and fluid intelligence are linked to the performance of children in the school setting. For these reasons, the goal of this work is to study the relation and contribution of perceptual, cognitive, and response inhibition with fluid intelligence, in children in the first years of primary school. For that purpose, a sample of children from six to eight years old (N = 178) was tested with a perceptual inhibition task (perception of similarities and differences task); a cognitive inhibition task (proactive interference task); a response inhibition task (stop signal task); and a fluid intelligence task (progressive matrices task). We observed significant correlations between perceptual and response inhibition and fluid intelligence (controlling for age), but only perceptual inhibition explains significantly part of the performance in the fluid intelligence task. This study provides data about the specific contribution, during childhood, of an inhibitory type to fluid intelligence and contributes empirical evidence in support of the non-unitary approach of inhibition.