Agroforestry systems include trees or shrubs and grasses and are considered a sustainable method of restoring degraded pastures, mitigating climate change, and increasing carbon and nitrogen stocks in tropical soils. Thus, the objective of this study was to quantify the carbon and nitrogen stocks in different agroforestry systems with forage cactus in the semi-arid tropic of Pernambuco. The experiment (8 years) was conducted on a Regosol soil at Caruaru Experimental Station, Agronomic Institute of Pernambuco - IPA (8º 14’ S and 35º 55’ W). The following cropping systems were tested: i) Gliricidia [Gliricidia sepium (Jacq.) Kunth] + forage cactus IPA Sertânia [Nopalea cochenillifera (L.) Salm-Dyck], and ii) Leucena [Leucaena leucocephala (Lam.) de Wit] + forage cactus IPA-Sertânia. Treatments were allocated in a complete randomized block design, with four replications. Samples were collected during the rainy seasons in the 0- to 0.10- and 0.10- to 0.20-m soil layers at 0, 1.5, 3.0, and 4.5 m in a perpendicular gradient from tree legume rows. Samples were used to determine soil carbon and nitrogen stocks. The different agroforestry systems did not differ significantly for C and N stocks. However, C and N stocks were significantly higher at the 0.10- to 0.20-m layer compared to the 0- to 0.10-m layer. It was observed that the 0.10- to 0.20-m layer stored an average of 36.6 Mg C ha-1 and 1.9 Mg N ha-1, while the 0- to 0.10-m layer stored an average of 14.7 Mg C ha-1 and 1.3 Mg N ha-1. It is concluded that the different cultivation systems with forage cactus are similar and efficient in storing carbon and nitrogen. The largest stocks of carbon and nitrogen occurred in the 0.10- to 0.20-m layer.