Chloroplast movements are controlled by ultraviolet/blue light through phototropins. In Arabidopsis thaliana, chloroplast accumulation at low light and chloroplast avoidance at high light intensities are observed. These responses are controlled by two homologous photoreceptors, phot1 and phot2. Whereas chloroplast accumulation is triggered by both phototropins in a partially redundant manner, sustained chloroplast avoidance is elicited only by phot2. Phot1 is able to trigger only a small transient chloroplast avoidance, followed by the accumulation phase. The source of this functional difference is not fully understood, either at the photoreceptor or signalling pathway levels. In this article, we review the current understanding of phototropin functioning and try to dissect the differences which result in signalling to two distinct chloroplast responses. In the first part, we focus on phototropin structure, photochemical and biochemical activity. Next, we analyse phototropin expression and localization patterns. We also summarize known photoreceptor systems controlling movements. Finally, we focus on the role of environmental stimuli in controlling phototropin activity. All those aspects impact the signalling to chloroplast movements and raise outstanding questions about their mechanism.