GO:0060392

Any process that decreases the rate, frequency or extent of SMAD protein import into the nucleus, i.e. the directed movement of a SMAD proteins from the cytoplasm into the nucleus. Pathway-restricted SMAD proteins and common-partner SMAD proteins are involved in the transforming growth factor beta receptor signaling pathways. [GOC:BHF, GOC:dph, GOC:tb]