Method for determining at least one parameter of a particle (10 i) present in a sample, the sample lying between an image sensor and a light source, the image sensor lying in a detection plane ( P 0), the method comprising the following steps: a) illuminating the sample with the light source, the light source emitting an incident light wave that propagates along a propagation axis; b) acquiring an image of the sample ( I 0) with the image sensor, the image sensor being exposed to an exposure light wave, the acquired image forming a hologram of the sample; c) determining a position ( x i, y i) of the particle in the detection plane or in a plane parallel to the detection plane; d) on the basis of the acquired image ( I 0), applying a holographic propagation operator (h), for a plurality of distances ( z) from the detection plane, so as to estimate, at each distance, a complex amplitude ( A ( x i, y i, z)) of the exposure light wave; e) on the basis of the complex amplitude estimated, at various distances ( z), obtaining a profile ( F x i, y i) representing a variation in the complex amplitude of the exposure light wave ( A ( x i,y i,z)) along an axis parallel to the propagation axis and passing through the position ( x i, y i) of the particle; the method being characterized in that the particle is associated with a set of parameters ( par), comprising at least a size of the particle and a refractive index ( n, Δ n) of the particle, the method also comprising: f) modelling a modelled particle (10( par)), taking into account a value of each parameter of the set of parameters ( par), and modelling an exposure light wave (14 mod), which would propagate toward the image sensor, under the effect of an illumination, with the light source, of the modelled particle; g) on the basis of the modelled exposure light wave (14 mod), forming a profile (F(par)) representing a variation in the complex amplitude of the modelled exposure light wave, along an axis parallel to the propagation axis; h) comparing the profile ( F x i,y i) obtained in step e) with the modelled profile (F(par)) resulting from step g), so as to determine the value of at least one parameter ( par i) of the particle. a) illuminating the sample with the light source, the light source emitting an incident light wave that propagates along a propagation axis; b) acquiring an image of the sample ( I 0) with the image sensor, the image sensor being exposed to an exposure light wave, the acquired image forming a hologram of the sample; c) determining a position ( x i, y i) of the particle in the detection plane or in a plane parallel to the detection plane; d) on the basis of the acquired image ( I 0), applying a holographic propagation operator (h), for a plurality of distances ( z) from the detection plane, so as to estimate, at each distance, a complex amplitude ( A ( x i, y i, z)) of the exposure light wave; e) on the basis of the complex amplitude estimated, at various distances ( z), obtaining a profile ( F x i, y i) representing a variation in the complex amplitude of the exposure light wave ( A ( x i,y i,z)) along an axis parallel to the propagation axis and passing through the position ( x i, y i) of the particle; f) modelling a modelled particle (10( par)), taking into account a value of each parameter of the set of parameters ( par), and modelling an exposure light wave (14 mod), which would propagate toward the image sensor, under the effect of an illumination, with the light source, of the modelled particle; g) on the basis of the modelled exposure light wave (14 mod), forming a profile (F(par)) representing a variation in the complex amplitude of the modelled exposure light wave, along an axis parallel to the propagation axis; h) comparing the profile ( F x i,y i) obtained in step e) with the modelled profile (F(par)) resulting from step g), so as to determine the value of at least one parameter ( par i) of the particle.