The aim of this paper is to analyse the dynamics relationships between inflation, output growth, and real and nominal uncertainty using the VARFIMA-BEKK MGARCH model of inflation and output growth and quarterly data for the UK covering the 1957:Q2-2006:Q4 period. The analysis is also done for the three sub-periods determined by considering the structural changes such as the Great Moderation in the series of the UK. Two findings are obtained. First, the evidence obtained from the full period supports a number of important conclusions, one of which is mixed evidence regarding the effect of inflation on inflation uncertainty, another one being strong evidence regarding the positive effect of inflation uncertainty on inflation and output growth. Taking this into account, it is possible to put forward that an essential determinant of economic growth is uncertainty about the inflation rate. The last finding for this period is that output growth uncertainty is a positive determinant of the inflation and output growth rate. Second, the evidence found from the sub-periods is that there are no linkages between inflation, output growth and their volatility.