Many intriguing physical phenomena have emerged from the Bi-containing materials due to the interplay of band topology and strong spin-orbit coupling (SOC). In this work, we report anisotropic spin-to-charge conversion in Bi, a semimetal endowed with highly anisotropic Fermi surfaces in addition to strong SOC. The value of spin Hall angle ${\ensuremath{\theta}}_{\mathrm{SH}}$ in Bi, that measures the spin-to-charge conversion efficiency, varies from ${\ensuremath{\theta}}_{\mathrm{SH}}\ensuremath{\approx}0$ to ${\ensuremath{\theta}}_{\mathrm{SH}}\ensuremath{\approx}2.6%$ for two predominant crystal orientations. In addition, the propensity of oxidation and interface quality also affect the spin-to-charge conversion in Bi. The highly anisotropic spin-to-charge conversion between Bi(003) and Bi(012) provide significant insights into the exploration and development of Bi-based topological quantum materials and spintronics.