The lattice parameters and composition range of orthorhombic CaTi _{1 - x} Cr _xO _{3 - δ} solid solutions were determined by x-ray powder diffraction. Samples with the nominal compositions CaTi _{1 - y} In _yO _{3 - δ}, synthesized in the range y=0.05-0.3, consisted of two phases: CaTiO _{3 - δ} and a CaIn ₂O ₄-based phase. The compositions of the synthesized phases were checked by x-ray microanalysis. The electrical conductivity of the CaTi _{1 - x} Cr _xO _{3 - δ} (0 < × ≤ 0.2)solid solutions was measured as a function of oxygen partial pressure (0.21 × 10 ⁴ to 1.0 × 10 ^-11 Pa) at 900 and 1000°C. Cr doping of calcium titanate was shown to increase its conductivity. A mechanism of defect formation in doped calcium titanate was inferred from conductivity versus p _o2 data.