The Senator's E grade in Mathematics was what caught the attention of many at the first glance of the results.
A section criticised him noting that he could just have 'hidden the rather embarrassing score' while some questioned his ability to handle the County's accounts with such results.
Others, however, congratulated the flamboyant politician for being bold enough to lay bare his weakness.
In response to his followers who were questinoning his knowledge of Mathematics, the Senator said: "hesabu ya pesa najua sana".
At the same time, some netizens cast doubt on the authenticity of the certificate stating that it was a forgery.
Those who questioned the Senator highlighted that his subject choice was inconsistent with the Kenya National Examination Council (KNEC) regulations. As per Sonko's result slip, he sat for both Geography and History yet the current norm is choosing between the two subjects.
Also, some faulted the codes of the subjects. However, a spot check by Kenyans.co.ke revealed that the subject codes on Sonko's results were in line with those of KNEC in 1992.
Eye-hawked Kenyans also noticed that the spelling of his name was also not consistent with the other certificates he posted.
Interestingly, some Kenyans drew inspiration from Sonko's below-average results concluding that good grades were not the basis of success in life.
Top Nairobi lawyer Ahmednassir Abdullahi also delved into the conversation when he saw that Sonko scored a Second Upper in his undergraduate degree.
Mr Abdullahi noted that: "...ati Sonko scored second class upper division...s*** hanging from a stick!!!!"
Sonko, who is eyeing the Nairobi gubernatorial seat, unleashed his certificates after claims that the Jubilee Party was plotting to block him from presenting his nomination papers.
According to the senator, there was a deliberate plan by the Criminal Investigation Department to delay the process of issuing him with a Certificate of Good Conduct, which is one of the requirements being demanded by the Party.
Here is the certificate: