This paper examines the growth of Portuguese industry throughout the XXth century, focusing on the dynamics of its productivity, measured by the ratio of value added to labor force. The analysis consists of: (i) construction of productivity indices for the Portuguese industrial sector and sub-sectors, as well as for the industrial sectors of fourteen European countries, covering the widest possible period within the century; (ii) identification of growth cycles for each productivity series, by means of estimation of trend growth rates; (iii) assessment of the contributions of each sector to the productivity dynamics in each growth cycle, using structural change analysis and international and inter-industries comparisons; (iv) appraisal of the results in the light of previous analyses of historical data.Portuguese industrial productivity has trended up systematically during the XXth century, but with well-differentiated growth phases matching the institutional changes that most markedly influenced the economy. The growth cycles clearly distinguish a first phase of weak growth, until the beginning of the 50s, from a subsequent phase of strong vitality and industrial modernization, especially in the manufacturing industry, ending in the mid-70s. A negative growth cycle follows, until the mid-80s, in which the consumption goods industries, with a large share in total industry, assured a minimum productivity threshold, in a context of severe reductions in the industries producing intermediate and capital goods. During the last fifteen years of the century, a new positive growth cycle emerged, led by some modern manufacturing sectors, although with a clear deindustrialization trend, ie of loss of production and labor force shares, in favor of services. The two phases of higher industrial productivity growth, 1951-1973 and 1985-2000, coincided to a large extent with institutional changes leading to openness and international integration, which proved to be crucial in enhancing the international tradability of industrial goods. When assessed in international perspective, with a focus on Europe, the performance of Portuguese industrial productivity is much less impressive, even during the cycle of higher growth and industrialization – 50s and 60s.Industrial productivity; Growth cycles; Structural change; Portugal.