Citrus is one of the major fruit crops in Cuba. Its perennial nature, the planted area and the time of productive exploitation turn it into a potential sink of atmospheric carbon. The present study was focused on the obtainment of two models that allow the quantitative estimation of carbon retention by citrus groves. The research was done in two commercial groves: orange [Citrus sinensis (L) Osbeck] cv. "Valencia Late" and grapefruit (Citrus paradisi Macf.) cv. "Marsh Seedless" both on sour orange (Citrus aurantium L.) and planted on a typical red ferralitic soil of Artemisa province. Groves are located at 22˚55' North and 82˚40' West. Cuba's climate is tropical, seasonally humid, with sea influence and semicontinentality features. Three issues were dealt with: 1) Determination of the total mean quantity of retained carbon by the aerial part of the trees using a destructive sampling method (Pattern Method) to estimate: the total volume of the tree, wood densities and green and dry biomass; 2) Determination of the total mean quantity of retained carbon by the aerial part of the trees using two Allometric Methods; and 3) Determination of the most effective Allometric Method to estimate the carbon retention by the aerial part of the trees. From the results, it is concluded that the evaluated methods were effective to reach a first quantitative approximation to carbon retention by citrus groves and under equal conditions, the Allometric Method 2 was more accurate to estimate the Total Carbon Content in "Valencia Late" orange, while for "Marsh Seedless" grapefruit the Allometric Method 1 provided the best estimate.