The dataset contains plant species occurrences recorded during fieldwork carried out from 2018 to 2019 in selected sites in Nyeri, Meru, Embu, Murang’a, Tharaka Nithi and Kiambu Counties all in the Upper Tana River Basin, Kenya. The sites included: Kiang’ondu Forest; Ngaya Forest; Kijegge Hill; Kathithini, Kamanyathi Location; Nkorongo River, Mwonyonzi, Chiakariga Location; Kiang’ombe Hill; Thegu, Gura, Sagana, Mathioya, Maragua, Channia, Chania and Thika Rivers; Gathabara, Mbuguti,and Mitai streams as well as Kimakia Forest in the Aberdares. The plants species were mainly identified on site to species level and documented as site records. However, in a few cases, voucher specimens were collected for confirmation and preservation at the East African Herbarium (EA), National Museums of Kenya, Nairobi. Geo-references were taken on site using a Garmin GPSMAP64s.