The ability to learn associations between sensory stimuli, actions and outcomes is crucial for adaptive perceptual decision-making. A key brain area supporting this ability is the striatum, which receives extensive signals from several cortical areas. These cortico-striatal pathways are shaped by two neuromodulators, dopamine and acetylcholine, whose levels are among the highest in the brain. Yet, how dopamine and acetylcholine interact to facilitate adaptive perceptual decision-making is unclear. To address this question, we characterized dopamine and acetylcholine release in the dorsolateral striatum in a visual decision-making task in head-fixed mice, using ultrafast fluorescent sensors with fiber photometry. We observed marked release of both dopamine and acetylcholine in response to visual stimuli, graded by stimulus difficulty. Both dopaminergic and cholinergic responses to stimuli depended on experience with the task, and were absent in naive mice. Moreover, dopamine and acetylcholine release was negatively correlated, consistent with previous studies. Crucially however, while dopamine release occurred to both contra- and ipsilateral stimuli, acetylcholine predominantly encoded contralateral stimuli. Conversely, while acetylcholine faithfully reported the presence of a stimulus regardless of whether animals used the stimulus to solve the task, dopamine responses reflected whether a stimulus impacted behavior. Thus, dopamine, unlike acetylcholine, was modulated by the behavioral strategy of individual animals. The two neuromodulators are therefore decorrelated during specific phases of perceptual decision-making, signaling distinct variables in a strategy-dependent manner. This decorrelation may enable the two neuromodulators to jointly regulate synaptic plasticity according to spatial and strategy-dependent aspects of the task, to facilitate adaptive perceptual decision-making.