Objectives of this study were aimed (i) evaluation of effects of fertilizing nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) on growth, yield and fruit quality of ratoon pineapple and (ii) adjustment of fertilizers for ratoon pineapple in acid sulfate soil in Long My district, Hau Giang province, whose formula was established by the site-specific nutrient management (SSNM). The experiment was performed a completely randomized block design, with eight treatments: (i) the control: no fertilization, (ii) NPKCaMg: fertilization of N, P, K, Ca and Mg, (iii) PKCaMg: omitting fertilization of N, (iv) NKCaMg: omitting fertilization of P, (v) NPCaMg: omitting fertilization of K, (vi) NPKMg: omitting fertilization of Ca, (vii) NPKCa: omitting fertilization of Mg, (viii) FFP: farmers’ fertilizing practice. In the result, omitting fertilizations of each of N, P, K or Mg shortened plant height. Omitting fertilizations of each of N, Ca or Mg decreased length and weight of fruit, while P omitting fertilization reduced only fruit weight, and N or Ca omitting fertilizations brought down fruit diameter. Omitting fertilization of each of N, P, K. Ca or Mg led to lowered quality of pineapple fruit. As against the full fertilization of NPKCaMg, omitting fertilizations of each of N, P, Ca and Mg resulted in lower pineapple yield, with a fluctuation of 28.4 - 31.5 t/ha compared to 39.7 t/ha. The established fertilizer formula of N, P, K, Ca and Mg for ratoon pineapple was 462 N, 341 P2O5, 510 K2O, 1207 CaO, 618 MgO kg ha-1.