  Electrical resistivity experiments show superconductivity at $T_c = 1.1\,$K
in a high-quality single crystal of trigonal $\gamma$-PtBi$_2$, with an
enhanced critical magnetic field $\mu_0H_{c2}(0) \gtrsim 1.5\,$Tesla and a low
critical current-density $J_c(0)\approx 40\,\mathrm{A}/\mathrm{cm}^2$ at $H=0$.
Both $T_c$ and $H_{c2}(0)$ are the highest reported values for stoichiometric
bulk samples at ambient pressure. We found a weak $H_{c2}$ anisotropy with
$\Gamma=H_{c2}^{ab}/H_{c2}^{c} < 1$, which is unusual among superconductors.
Under a magnetic field, the superconducting transition becomes broader and
asymmetric. Along with the low critical currents, this observation suggests an
inhomogeneous superconducting state. In fact, no trace of superconductivity is
observed through field-cooling--zero-field-cooling magnetization experiments.
