Method for detecting accidents of vehicles, comprising the following steps: - detecting a plurality of acceleration values (A x, A y, A z) of a vehicle along respective directions; - comparing said acceleration values (A x, A y, A z) with at least a predefined acceleration threshold value (A thx, A thy, A thz); if at least one of said acceleration values (A x, A y, A z) is bigger than or equal to said acceleration threshold value (A thx, A thy, A thz): - initializing a temporal variable t=0; - calculating a plurality of speed values by means of the formula V i (t)=V i (t-Δt)+A i ∗ Δt, where: i means said directions of detection of the acceleration values (A x, A y, A z); V i (t) are said speed values calculated at a temporal instant equal to t; V i (t-Δt) are said speed values calculated at a temporal instant equal to t-Δt; A i are said acceleration values; Δt is a predefined sampling range; - determining a plurality of speed variation values (ΔV x, ΔV y, ΔV z) starting from said speed values (V x (t), V y (t), V z (t)) and from at least a previous speed value (V x (t-ΔT w), V y (t-ΔT w), V z (t-ΔT w)); - determining a speed vector module (|V(t)|) by means of the formula |V(t)|=√(Σ(ΔV i 2)), where: |V(t)| is said speed vector module, ΔV i are said speed variation values, where i shows said directions of detection of the acceleration values (A x, A y, A z); - comparing said speed vector module (|V(t)|) with at least a speed threshold value (ΔV th) and, if said speed vector module (|V(t)|) is bigger than or equal to said speed threshold value (ΔV th), signalling the detection of an accident on said vehicle; - if said speed vector module (|V(t)|) is lower than said speed threshold value (ΔV th) and if said temporal variable (t) is lower than a predefined measurement temporal interval, repeating said steps of detecting, calculating, determining a plurality of speed variation values (ΔV x, ΔV y, ΔV z), determining a speed vector module (|V(t)|) and comparing, for t=t+Δt. - detecting a plurality of acceleration values (A x, A y, A z) of a vehicle along respective directions; - comparing said acceleration values (A x, A y, A z) with at least a predefined acceleration threshold value (A thx, A thy, A thz); - initializing a temporal variable t=0; - calculating a plurality of speed values by means of the formula V i (t)=V i (t-Δt)+A i ∗ Δt, where: i means said directions of detection of the acceleration values (A x, A y, A z); V i (t) are said speed values calculated at a temporal instant equal to t; V i (t-Δt) are said speed values calculated at a temporal instant equal to t-Δt; A i are said acceleration values; Δt is a predefined sampling range; i means said directions of detection of the acceleration values (A x, A y, A z); V i (t) are said speed values calculated at a temporal instant equal to t; V i (t-Δt) are said speed values calculated at a temporal instant equal to t-Δt; A i are said acceleration values; Δt is a predefined sampling range; - determining a plurality of speed variation values (ΔV x, ΔV y, ΔV z) starting from said speed values (V x (t), V y (t), V z (t)) and from at least a previous speed value (V x (t-ΔT w), V y (t-ΔT w), V z (t-ΔT w)); - determining a speed vector module (|V(t)|) by means of the formula |V(t)|=√(Σ(ΔV i 2)), where: |V(t)| is said speed vector module, ΔV i are said speed variation values, where i shows said directions of detection of the acceleration values (A x, A y, A z); |V(t)| is said speed vector module, ΔV i are said speed variation values, where i shows said directions of detection of the acceleration values (A x, A y, A z); - comparing said speed vector module (|V(t)|) with at least a speed threshold value (ΔV th) and, if said speed vector module (|V(t)|) is bigger than or equal to said speed threshold value (ΔV th), signalling the detection of an accident on said vehicle; - if said speed vector module (|V(t)|) is lower than said speed threshold value (ΔV th) and if said temporal variable (t) is lower than a predefined measurement temporal interval, repeating said steps of detecting, calculating, determining a plurality of speed variation values (ΔV x, ΔV y, ΔV z), determining a speed vector module (|V(t)|) and comparing, for t=t+Δt.