In this paper, a complete solution to the fracture problem of double cantilever beams (DCBs) made of generally orthotropic materials under transverse shear loading has been derived with full consideration of the effects of shear deformation and crack-tip rotation. The solution set, which includes analytical expressions for energy release rate (ERR) calculation, fracture load and displacement as functions of material orthotropy and crack length, is applicable to all practical orthotropic materials and is accurate for both long and short beams. Using the derived analytical expressions, the compliance method for determining fracture toughness has been re-examined. An important finding is that the effective crack length for computing ERR cannot be used without modification for computing specimen compliance. An expression for the effective crack length that can be used for assessing specimen compliance has been derived. The expression is within 3% of uncertainty for practical orthotropic DCBs with both short and long crack.