Measurements of lattice diffusion coefficients for 44Ti in niobium single crystals were made in the temperature range of 994-1492°C using an anodizing-stripping sectioning technique. The temperature dependence of the diffusion coefficients within this range follows an Arrhenius relation and can be expressed as Exp[-(86930 ± 2160)/RT] cm 2/sec. Non-linear penetration profiles were observed, composed of two or three segments depending whether near surface effects were present or absent. The near surface effect observed in this work is the result of an artifact and not an intrinsic property of the Nb-Ti system.