Crystal morphology of thermoplastics is known to be strongly influenced by the presence of solid substrates like fibers or fillers. For wood, this interphase development is governed by the chemical composition of the thermoplastic and substrate. The crystallization of PP/MAPP blends was observed using polarized light microscopy and quantified using DSC and DMA. Techniques are presented to assess degree of crystallinity and temperatures associated with the onset (T-O) and maximum rate (T-C) of crystallization using DMA. Strain history of the specimen during crystallization was evaluated and does not significantly influence either T-O or T-C. Crystallization temperatures of PP as assessed using DSC or DMA increase with the addition of MAPP or the presence of wood. Values for T-C are higher when measured by DMA than DSC. This difference appears to be related more to the relative interfacial dominance in the specimens, rather than to an inherent difference between techniques.