Interspecific hybridisation of Elaeis oleifera (O) and Elaeis guineensis (G) oil palm was done to create recombinant progenies, containing various composition of parental genetic material. Genomic in situ hybridisation (GISH) on OxG hybrids had previously shown presence of 16 E. oleifera and 16 E. guineensis chromosomes. In this study, GISH was used to examine the metaphase chromosomes of the OxG interspecific hybrids hybridised with E. guineensis [(OxG)xG] to produce backcross one (BC1) progenies. Optimisation of unlabelled E. guineensis genomic DNA quantity were required to produce optimum discrimination of the E. oleifera and E. guineensis chromosomes. The amount needed was 120 μg indicating the high genome similarity. The chromosomes of BC1 individuals were 2n=32 and consisted of variable composition of E. oleifera and E. guineensis chromosomes while the interphase nuclei showed regions of parental genomes in discrete, non-intermixed domains indicating non-random organisation of the nucleus. The seedlings were created to assist in GISH analysis, hence, only leaflet plane correlation with the number of E. oleifera chromosomes transmitted into the progenies were done. No correlation can be observed between the numbers of E. oleifera chromosomes and the leaflet plane.