Data are presented for Above ground Carbon Density (ACD) estimated from a series of forest census surveys which took place from 1992- 2016 in a mixture of logged and unlogged tropical lowland dipterocarp forest in the Ulu Segama Forest Reserve (USFR) and Danum Valley Conservation Area (DVCA), Sabah, Malaysia. Additional data on logging method, coupe and year of logging is also presented. The USFR comprises of forested land divided into coupes that were each logged once, between 1972 and 1993 using either "tractor" or "high-lead" methods. Between 1993 and 2004, forest restoration treatments were carried out, including climber cutting and tree planting, annually across logging coupes within the USFR. The data-set was compiled from census carried out in three independent plot networks. The first led by researchers from the Universities of Dundee, Aberdeen and Nottingham. The second led by researchers from the University of Aberdeen. The third through the INnoprise FAce PROject INFAPRO project. Between 1992 and 2016 a forest census survey was carried out on at least two occasions in 553 forest plots to determine the rate of ACD accumulation and understand the impact of forest restoration treatments on ACD accumulation. Tree stem diameter, height and identity measurements at each plot were collected by project members and research assistants employed by the SouthEast Asian Rainforest Research Partnership (SEARRP). The ACD carbon estimation and modelling was led by researchers from the Universities of Dundee, ETH Zurich and Aberdeen. The data were compiled and submitted by researchers from the University of Dundee and ETH Zurich. Funding for the establishment of the original plot networks was provided by the EU-funded INDFORSUS project (ER-BIC18T960102), from New England Electric Systems, National Geographic Society and the Garden Club of America, and from Face the Future Foundation. Funding for the repeated measurements was provided by the NERC "Spatio-TEmporal Dynamics of Forest Response to ENSO Drought (STEED)" (NERC grant reference NE/P004806/1) and the Carnegie Trust for the Universities of Scotland funded project"Changing species diversity and biomass accumulation in conserved and regenerating tropical forests: two decades on". Full details about this dataset can be found at https://doi.org/10.5285/a75e6371-a931-4676-9199-d1f5af565ab2