As the most common lethal cancer in women worldwide, breast cancer remains a research priority. If the involvement of ion channels in cell signaling pathways leading to cancer is now well established, the role of inositol (1,4,5)-trisphosphate (IP3) receptors (IP3Rs) remains enigmatic. In this context, we investigated the involvement of the three IP3Rs (IP3R1, 2 & 3) in migration processes of human breast cancer cells. Migratory behavior of cancer cells was measured by transwell migration assays and circularity indices determination on three breast cancer cell lines: the low-migrating MCF-7 cell line (1 ± 0.66, N=3) and the highly migrating and invasive MDA-MB-231 (15.43 ± 1.33 for MDA-MB-231 (N=3, P=0.001) vs MCF-7) and MDA-MB-435s cell lines (25.48 ± 1.59 for MDA-MB-435s, (N=3, P=0.0006 vs MCF-7 and P=0.012 vs MDA-MB-231). Using Q-PCR and western-blot approaches, we demonstrate that a higher IP3R3 expression level is correlated to a stronger migration faculty of the cell lines. IP3R1 & 2 appear equally expressed in MCF-7 like in MDA-MB-435s cells. Gene silencing of IP3R3 (siR3) in MDA-MB-231 and 435s leads to a significant decrease of their migration abilities (0.57 ± 0.13 vs. 1 ± 0.24 (N=3, P=0.04) for siR3 and siC conditions in MCF-7, 0.53 ± 015 vs 1 ± 0.05 (N=3, P=0.03) for siR3 and siC conditions in MDA-MB-231, and 0.08 ± 0.17 vs 1 ± 0.06 (N=3, P=0.001) for siR3 and siC conditions in MDA-MB-435s) without changing their proliferation rate. Conversely, stable overexpression of IP3R3 in MCF­7 cells significantly increases their migration capacity, this latter effect being completely reversed by siR3. The additive effect of ATP increasing migration in these IP3R3 overexpressing cells was also abolished by IP3R3 silencing. Interestingly this IP3R3 dependent modulation of migration capacities was not observed with IP3R1 or IP3R2 silencing in all cell lines. As a key effector in migration process, we then investigated the calcium signaling in these three cell lines. Calcium imaging assays reveal an increasing calcium resting ratio according to cellular migration capacities (0.59 ± 0.015 for MCF-7 (n=81), 1.22 ± 0.009 for MDA-MB-231 (n=134) and 1.45 ± 0.01 for MDA-MB-435s (n=67)). IP3R3 silencing causes a drastic modification of the temporal feature of ATP (5 µM)-induced Ca2+ signaling in the three cell lines, displaying a pattern of sinusoidal Ca2+ oscillations instead of a plateau phase. This calcium signature was specific to IP3R3 as it could not be observed by IP3R1 or IP3R2 silencing. It can therefore be hypothesized that the migration capacity of cells could be related to the temporal feature of the IP3R3 dependent Ca2+ signal. Altogether, our results demonstrate that IP3R3 expression level modulates the migration capacity of human breast cancer cells and led us to propose IP3R3 as a key target in cancer migration processes.