The notion of defect for finite algebraic extensions of valued fields is classical and due to Ostrowski. Recently Matignon has generalized Ostrowski's definition to rk 1 (residually transcendental) valued function fields and used it to prove a very sharp version of the genus reduction inequality for 1dim function fields. The further generalization of the notion of defect to valued function fields of arbitrary rk is treated here. Let (K/Ko , v) be a valued function field of dim n, i.e., K/Ko is a finitely generated field extension of deg of transcendence n and v is a valuation of K. Let V5 c V, ko c k, and Go c G be the respective valuation rings, residue fields, and value groups of the extension Ko c K; and let * denote image under the v-residue map V Vl/mr = k. A transcendence basis t = {t1, ... , tn} of K/Ko will be called a residually transcendental (abbreviated tr.) basis of the valued function field if v(ti) > 0 (i = 1, ...,n) and the set of v-residues t* = {t*, ...,t} is algebraically independent over ko. The function field will be called residually tr. if there exists a residually tr. basis. A transcendence basis t is residually tr. iff v IKo(t) is the inf extension, denoted vt, of v0 w.r.t. t, i.e., iff for all f(t) in KO[t], v(f) = the inf of the values of the coefficients of f. Note that the value group of vt is clearly GO) and the residue field is ko(t*). (Cf. [3, p. 161, Proposition 2].) If t is a residually tr. basis, the henselian defect at t is defined to be D (t) := [K h: KO(t)h]/IR, where Kh denotes henselization, I = [G: GO], and R = [k: ko(t*)]. We shall prove here the 0. Independence Theorem. Let (K/KO , v) be a residually tr. valued function field. Then Dh (t) is independent of the choice of residually tr. basis t. The case that K/Ko is simple tr. has been proved in [13, Theorem 2.2]. Also, Matignon [10, p. 191, Corollary 1] has proved that if rk v = 1, then the Received by the editors July 5, 1988. 1 980AMathematics Subject Classification (1985 Revision). Primary 1 3A18, 12F20.