Precious Blood Kagwe is a catholic sponsored extra-county public school. It was started in 1966 at the request of the people of Gatamaiyu. Its under the Catholic Archdiocese of Nairobi. It was started by the missionary sisters of Precious Blood.

The first form 1 class was started on 11th February 1966 with 18 students under Sr. Silvana. She managed the school from 1966 to 1971. One of the achievements during this period is the students population increased to 148.
The features in the facility grew as the general science laboratory and the needle work room were put up from the primary school. In 1970 the provincial inspector Mr. Grieves Cook declared it the best Harambee School.
The students sat for the first EACE in 1971 where 18 students out of 21 candidates passed.
In 1972 the first 30 students started the boarding section in a timber building. In 1972, the Archbishop of Nairobi opened the laboratory and hostel buildings. In 1977 the library was built. Sr. Mlanatis C.P.S took over in 1972 up to 1979, Sr. Engelberta Frohlich headed the school from 1980 to 1989. In 1980 H.E. President Daniel Toriotich Arap Moi visited and donated the funds to the school. In 1981, the house system was introduced with 5 houses. Students were awarded merits for good conduct and demerits for broken school rules.
In 1982 H.E. President Daniel Toroitich Arap Moi opened a storey building to accommodate 128 girls. Infrastructure grew in the school between 1985 to 1990 which consisted of the construction of the kitchen dining hall, classrooms, staff houses, science laboratories and computer building.
Sr. Maria Pacis Vogel took over in February 1989 to November 1991. Sr Anne Walton headed the school from 1991 to April 2006. The school attained a 33 seater bus in 1999.
The school has excelled in curriculum and Co-Curricular activities. Students have participated up to National level in Science Congress, Sports and Music Festivals. In the year 2000, the  school attained the school of the year award due to its KCSE performance. The students visit nyumbani home which is home to HIV/AIDS infected babies, every term.
The school encourages students to explore their talents through clubs, movements, societies and games.
Mrs. Esther Mathenge took over in May 2006 to December 2006. Mrs. Rose Kiragu took over from her from January 2007 to May 2013.
In December 2007 proposed classroom, department offices, exam room building started. In 2010, the computer room was converted into Administration block which is now the principal office.
The school attained the school van 2011 through CDF LARI. In 2012, the school was registered as a three stream and the name changed to Precious Blood Kagwe.
On 22nd February 2012 by the help of zonal forest manager, Mr. Njenga, the school started the construction of Biogas, on 23rd November the same year, the school received donations of computers from UNEP.
Mrs. Joy Gitonga took over in May 2013 after the transfer of Mrs. Rose Kiragu to Kerugoya girls. The water heating system was then installed. In the same year, Mr. Eliud Muriithi sponsored the sign boards. Bulk sms were introduced and the electric bell.
Mrs. Lucy Mwangi took over from Mrs. Joy Gitonga in January 2019. Currently the school has a population of 883 students. It’s a five streamed school a population of 20 TSC teachers and 16 BOM teachers.
A modern dormitory to accommodate 400 students was completed in 2017. This was started with a harambee presided over by Hon. William Samoei Ruto on 10th July 2015.