Transient growth due to non-normality is investigated for the Taylor-Couette problem with counter-rotating cylinders as a function of aspect ratio η and Reynolds number Re. For all Re ≤ 500, transient growth is enhanced by curvature, i.e. is greater for η < 1 than for η = 1, the plane Couette limit. For fixed Re < 130 it is found that the greatest transient growth is achieved for η between the Taylor-Couette linear stability boundary, if it exists, and one, while for Re > 130 the greatest transient growth is achieved for η on the linear stability boundary.Transient growth is shown to be approximately 20% higher near the linear stability boundary at Re = 310, η = 0.986 than at Re = 310, η = 1, near the threshold observed for transition in plane Couette flow. The energy in the optimal inputs is primarily meridional; that in the optimal outputs is primarily azimuthal. Pseudospectra are calculated for two contrasting cases.For large curvature, η = 0.5, the pseudospectra adhere more closely to the spectrum than in a narrow gap case, η = 0.99.