Starch is an important biopolymer with a polymeric mixture of essentially linear (amylose) and branched (amylopectin) β-glucans. Pinhão seeds are from Paraná pine and grow in native forests of southern Latin America. The range of industrial applications of pinhão starch can be widened by applying heat-moisture treatment (HMT) to modify its functionality and physical organization. The pinhão starch was adjusted to 15 and 25% moisture content and heated to 100, 110 and 120 °C for 1 h. The granular and crystalline structure was characterized using scanning electron microscopy (SEM), size distribution was determined via Gel-permeation chromatography, and conformational changes were monitored via Fourier transform infrared spectroscopy (FTIR). SEM showed that HMT induced collapsed and aggregated granules upon heating (25% moisture content, 120 °C). Native Pinhão and HMT treated starch showed a similar chain size distribution of 26% of amylase. A decrease in λ max was observed as a result of increase in temperature and moisture content. The FTIR spectrum of native and HMT treated starch showed nine major distinct bands in the region of 1300-800 cm-1 at similar frequencies where bands at ca. 1045, 1016 and 995 cm-1 were related to the amount of crystalline starch and moisture content. The ratio of amorphous to crystalline phase in the pinhão was achieved via spectral deconvolution of band ratio of 1016 /1045 cm-1. The ratio of 1016 /1045 cm-1 increased as a result of HMT, favouring amorphous structure formation. These results may broaden the application of pinhão starch in food industry.