The aim of this paper is to examine the diatopic variation of some Sardinian complex predicates, mainly from a morphosyntactic (and, secondarily, a semantic) perspective. I will discuss (i) the distribution of Camp(idanese) ai / Log(udorese)-Nu(orese) àere a + inf(initive), lit. ‘to have to’ + inf., and of the agglutinated and univerbated forms of Log.-Nu. dèvere / dèppere + inf., lit. ‘must’ + inf., both constructions expressing (different types of) future time reference; (ii) the diffusion of person and number in the modal complex predicate Camp. fai / Log.-Nu. fàghere / fàchere a + inf., lit. ‘to do to’ + inf., with the sense of ‘being able/allowed to do something’; (iii) cases of double accusative marking of clitic pronouns expressing causee/beneficiary and undergoer , and agreement between these pronouns and the past participle of ‘make’/‘let’ in the causative constructions Camp. fai / Log.-Nu. fàghere / fàchere + inf., lit. ‘to make’ + inf., and Camp. lassai / Log.-Nu. lassare / (dassare) + inf., lit. ‘to let’ + inf.; (iv) the ongoing diffusion of the reiterative and/or purposive values of Camp. torrai a / po / Log.-Nu. torrare a / pro + inf., lit. ‘to return to’ + inf.; (v) the ongoing diffusion of the aspectual complex predicate Camp. (am)megai / Log.-Nu. (am)megare de / a + inf., conveying progressive aspect, according to Blasco Ferrer (1991; 2002) and my data. In conclusion, I will argue that isoglosses of morphosyntactic variation of Sardinian complex predicates seem to be more ‘conservative’ (in the sense of Virdis 1988) and to englobe wider and more homogenous areas, if compared to phonological isoglosses.