Keywords:Coherent pairs Structure relations Regular linear functionals Orthogonal polynomials Classical orthogonal polynomials Sobolev orthogonal polynomials Monic Jacobi matrix a b s t r a c t A pair of regular linear functionals ðU; VÞ in the linear space of polynomials with complex coefficients is said to be an ðM; NÞ coherent pair of order m if their corresponding sequences of monic orthogonal polynomials fP n ðxÞg nP0 and fQ n ðxÞg nP0 satisfy a structure relationwhere M; N, and m are non negative integers, fa i;n g nP0 ; 0 6 i 6 M, and fb i;n g nP0 ; 0 6 i 6 N, are sequences of complex numbers such that a M;n -0 if n P M; b N;n -0 if n P N, andVÞ is called an ðM; NÞ coherent pair.In this work, we give a matrix interpretation of ðM; NÞ coherent pairs of linear function als. Indeed, an algebraic relation between the corresponding monic tridiagonal (Jacobi) matrices associated with such linear functionals is stated. As a particular situation, we ana lyze the case when one of the linear functionals is classical. Finally, the relation between the Jacobi matrices associated with ðM; NÞ coherent pairs of linear functionals of order m and the Hessenberg matrix associated with the multiplication operator in terms of the basis of monic polynomials orthogonal with respect to the Sobolev inner product defined by the pair ðU; VÞ is deduced.