Information on the influence of date of planting on protein, oil and fatty acid composition of soybean seeds is meagre, whilst similar studies on lipoxygenase isozymes and trypsin inhibitor contents are lacking. A field experiment was conducted with nine Indian genotypes and three planting dates (spread over 23 days) to study the influence of planting dates on these seed traits. Results based upon a one-year study indicated that oil content declined with delays in planting. Oleic acid content increased from the first to third planting, while the reverse trend was observed for linolenic acid. Lipoxygenase-1 activity was reduced by delayed plantings. Protein content was the lowest and trypsin inhibitor content was the highest for the second planting. However, no differences were observed for protein and trypsin inhibitor contents between the first and third planting. Significant interactions. observed between genotype and planting date for most of the seed compositional characters suggest that the influence of late planting is genotype-dependent.