We used a chronometric transcranial magnetic stimulation (TMS) approach to study at which specific time window the lateral occipital (LO) cortex is causally involved in symmetry encoding. Healthy individuals were presented with a series of dot configurations and instructed to judge whether they were symmetric or not while receiving a double pulse of TMS over either the rLO or the vertex (baseline) at different time windows. In the present dataset mean accuracy scores (expressed as percentage of correct responses) and mean response time for correct response (expressed in millisecond) are reported for each participant. The results show that LO is causally involved in symmetry perception in two distinct time windows: between 130-170ms and between 210-250ms from the target onset, thus providing a causal temporal link between LO and well-known ERP components related to symmetry.