They are the ones seen as demanding payment for things like giving a student a passing grade or holding a place at university.
Here is the angry mother of an Uzbek student forced to pay money to ensure her daughter gets acceptable marks.
"It has gotten so bad that the teachers simply ask [the students] what grade they need. It's now at the point where there is no difference between a 'Three' ('C') student and a 'One' ('A') student," the mother said.
Another Uzbek woman says she has to pay in order that her child can enter university: "Our children are growing up and what can we do? We don't know. It costs a lot of money to go to school, and if you go to any university they are selling the [answers to] the tests."
It would be wrong, however, to cast all the blame simply on corrupt teachers. All the Central Asian countries have had to institute budget cuts since independence, and many of the cuts have come in education. Teachers and school administrators have seen their relative wages drop -- and bribes increasingly are needed for teachers make ends meet.
And frequently more subtle motives are also at work. In Uzbekistan, teachers say the corruption is so widespread there's no incentive to attempt reforms. Much easier, they say, is simply to take bribes and pass students along.
An Uzbek university professor tells RFE/RL it's much harder to enforce academic standards and provoke the wrath of bureaucrats. It's simpler to take the money and stay quiet.
"[At] some universities it is just that way. I can't blame the teachers for [demanding bribes] because there are some students who do not attend courses. The university cannot kick them out because they do not have the right. According to the contract, [the students] pay the tuition and get to stay in school. If we [teachers] try to [enforce stricter academic standards] the ministry of education could bring charges against us," the university professor says.
In Turkmenistan, constant interference from the government creates a special problem of low morale. Course materials are tightly controlled and teachers in many subjects are required to add the writings of the "Rukhnama" -- the Turkmen president's own book -- to the curriculum. In this atmosphere, change feels pointless, says one Turkmen teacher.
"In contrast to the other Central Asian countries, the problem in the system of education is not only in the budget deficit, but in government policy -- a policy, I believe, that is not correct," the teacher says
Nor is the matter always one of altruistic students forced to pay bribes to corrupt administrators. Students, too, often choose to abuse the system by buying good marks in courses they are weak in or don't want to study for. Here is a Tajik girl who says she paid a bribe to pass a difficult subject.
"I passed one exam, it cost 10 somoni (about $3). The cost of passing exams is usually 10 to 20 somoni. It was a difficult course and I had to pay. My parents don't know, they'd be upset if they knew I paid to pass my course," she says.
To be sure, there are still students who say hard work and intelligence are enough to succeed. A group of Uzbek students tells RFE/RL that, in general, if you study you don't have to pay.
"It is not always necessary to pay, so I don't know [what all the concern is about]," one student says
A second student says, "I got in [to university] without paying. There are teachers who take bribes, but not all. In every school there are students who know there's nothing else you can do. There are students who do not know [much] or do not study and they have to pay."
"I haven't paid anything to my teachers. I didn't give them any reason [to demand a bribe from me]," a third student says.
The tragedy of corruption in education, however, is that while it's often hard to identify the good from the bad guys -- in the end, everyone loses. Professional and educational standards suffer. Students lose the chance of learning. In the next part, part three, of our series on corruption in education, we take a closer look at the consequences.
(The Kazakh, Kyrgyz, Tajik, Turkmen, and Uzbek services contributed to this report.)