The Shore experiences periodic and seasonal changes caused by both natural and anthropogenic processes which include tidal inundation, rain and wave actions, sea level rise occasioned by climate change, dredging, reclamation, erosion and flooding activities. Shoreline mapping and change detection is essential for safe navigation, resource management, environmental protection and sustainable coastal development and planning. This study mapped the shoreline to determine the impact of human activities along the Port Harcourt shoreline from the year 1986-2015 using Satellite imageries and Real Time Kinematics Global Positioning System. Multi-temporal Landsat imageries of the study area for the years 1986, 2000, and 2013 were preprocessed and interpreted in ENVI4.5 software while the GIS operations were carried out using ArcGIS10 software, to identify the linear changes along the shoreline of the study area, using change detection method of image analyses. The RTK-GPS instrument was used to obtain the direct co-ordinates of specific portions along the Port Harcourt Shoreline in 2015.This was compared with those obtained with satellite data. The results show linear changes of between 66m to 209m at the specific portions observed from 1986 to 2015. The study showed that the techniques of Satellite Remote Sensing and RTK-GPS can be adequately used in mapping the impact of human activities on the shoreline. It is therefore recommended that the shoreline be monitored regularly to ascertain impacts of anthropogenic processes on the shore.