For his work in applied chemical science on rutile sand, phosphate rock, graphite and beryl "which has contributed to the advancement of the welfare of the community", McTaggart was awarded the University of Melbourne's Grosvenor Laboratories Prize for 1946 by the Royal Australian Chemical Institute; and the Grimwade prize in industrial research for 1946 for his "Mineral Chlorination Studies.” He was among the first CSIRO officers to be awarded an honorary doctorate.