Identification of the suitable genotype for somatic embryogenesis in soybean culture is very important for further application in Genetic Improvement Programs. The objective of the investigation was to determine the effect of the orientation and length of immature cotyledons in the formation of somatic embryos of two Cuban soybean genotypes (Incasoy-24 and Incasoy-35). The genotype Williams-82 was included as control. Two orientations were evaluated: abaxial and adaxial, as well as five lengths of the immature cotyledons: 2.0, 3.0, 4.0, 5.0 and 6.0 mm. Results demonstrated that the orientation and seed size are determinant in the number of somatic embryos formed in the Cuban genotypes evaluated. The highest values of somatic embryos per cotyledon were obtained in abaxial orientation. The highest embryogenic response was achieved using cotyledons of 4.0 mm length. These results provided basic information for further researches in this crop. Keywords: abaxial orientation, regeneration, somatic embryogenesis