The level structure of $^{178}\mathrm{Hf}$ has been studied via $\ensuremath{\gamma}$ singles, $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$ coincidences in the 2048 \ifmmode\times\else\texttimes\fi{} 4096 channel mode, and $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$ directional-correlation measurements with Ge(Li) detectors from the decay of $^{178}\mathrm{Ta}$. These data yielded 7 new transitions and the addition of 13 transitions to the decay scheme, which includes 5 new levels. The following levels were observed (energies in keV followed by the spin and parity): 93.13, ${2}^{+}$; 306.52, ${4}^{+}$; 1174.64, ${2}^{+}$; 1199.24, ${0}^{+}$; 1276.54, ${2}^{+}$; 1309.91, ${1}^{\ifmmode\pm\else\textpm\fi{}}$, ${2}^{+}$; 1362.36, ${2}^{(\ensuremath{-})}$; 1433.97, ${0}^{+}$; 1443.86, ${0}^{+}$; 1496.02, ${2}^{+}$; 1513.64, ${1}^{\ifmmode\pm\else\textpm\fi{}}$, ${2}^{+}$; 1561.27, ${2}^{+}$; 1566.45, ${1}^{\ifmmode\pm\else\textpm\fi{}}$, ${2}^{\ifmmode\pm\else\textpm\fi{}}$; and 1771.95, ${0}^{+}$. $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$ directional correlations were measured with the ${2}^{+}$ \ensuremath{\rightarrow} ${0}^{+}$, 93.13-keV transition and eight transitions that feed the first excited state. From the $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}(\ensuremath{\theta})$ data, spins of 2 and 0 are established for the 1362.36-and 1771.95-keV levels and $M1$ admixtures of ${85.6}_{\ensuremath{-}1.7}^{+1.2}$ and 65.2 \ifmmode\pm\else\textpm\fi{} 3.2% for the 1183.40- and 1402.87-keV transitions. With these multipole admixtures, the branching ratios for the ${K}^{\ensuremath{\pi}}I={0}^{+}2$, 1276.54-keV level cannot be brought into agreement with theory for a single ${Z}_{\ensuremath{\beta}}$ band-mixing parameter; while for the ${K}^{\ensuremath{\pi}}I={0}^{+}2$, 1496.02-keV level they can be.