Coconut water (Cocos nucifera L.), the semi-clear liquid endosperm obtained from immature coconut is a refreshing, nutritious beverage having beneficial health properties, used as an important alternative for oral rehydration and even for patient intravenous hydration in remote regions. It contains many PGRs which play vital roles in many processes during seed development such as histodifferentiation, reserve accumulation, and germination. Many literatures are available highlighting the levels of PGRs in the tender and mature coconut water. However, a detailed account on the dynamics of PGRs during the coconut seed development and a comparative analysis of PGRs in the parental cultivars and their reciprocal hybrids is lacking. In the present study, fifteen hormones belonging to seven major classes of phytohormones, viz., IAA, IBA, SA, GA?, GA?, GA?, tZ, tZR, BA, ABA, ACC, JA, cisJ, meJ, and 24-epiBL, were simultaneously assayed from the liquid endosperm of 120 days old young nuts collected from West coast tall cultivar, Gangabondam (dwarf cultivar)and their reciprocal hybrids (TxD and DxT)by LC-MS/MS method. According to the results, IAA was the predominant auxins while BA was the predominant cytokinins in the liquid endosperm of all cultivars and hybrids. SA was found in exceptionally higher levels in all the cultivars and hybrids. cisJ and 24-epiBL were found in significant levels in the tender coconut water. These PGRs were found to be involved in the histodifferentiation process of seed development. All GAs and ABA were found in insignificant level in the liquid endosperm of all the cultivars and hybrids indicating their insignificance in early embryogeny process of nut development.