Abstract: Comparative analyses were carried out on observational rainfall datasets over the Niger Delta region (4.15°N-7.17°N, 5.05°E-8.68°E) using six locations within the area for a period of 24 years (1981-2004). Monthly rainfall gridded datasets of the Climatic Research Unit-Time Series (CRU-TS) 3.20 and the Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) were compared with the Nigerian Meteorological Agency (NIMET) monthly rain gauge data as the reference. The objectives were to compare the representation of the gridded datasets in small areas, highlighting their similarities and differences on monthly rainfall variability as well as to examine that how these datasets compare with each other in representing the regions annual and wet season interannual rainfall variability. A mapping of rate of change in trend from the signatures of each dataset in representing the normalized monthly anomalous moisture flux accumulation (Ĉ) within the region was done using the potential evapotranspiration data from CRU TS 3.20. The three datasets show significant similarity in the trends of rainfall variability at each of the locations as well as on the areal average over the region. The annual and wet season interannual rainfall variability indexes from the NIMET rain gauges show significant correlation with the gridded datasets. However, the systematic differences in the gridded datasets as well as their relative accuracy and expected uncertainties have been compared to the rain gauge measurements. The three datasets confirm increment in the rate of change in the trend of Ĉ although with CMAP indicating higher reservoir of moisture flux accumulation than CRU when compared to the NIMET over the region. This study should guide researchers to carrying out studies in small areas of this scale on the choice of the rainfall observation gridded datasets for use in various applications.