"Whenever they discover something on the testicles they should go immediately to their doctor and maybe they will be as lucky as me.
"It only took three or four months after I was diagnosed and now I am back in life and back in sport. And I believe I will back in top sport again soon."
The Czech added: "I would like to tell them that this kind of cancer can happen to them. Everyone thinks prostate and testicular cancer is for old people.
"It's not. Testicular cancer is the same thing the cyclist Lance Armstrong had a problem with and many other athletes."
Koukal was speaking at the Yonex BWF World Championships at Wembley Arena this week where he lost in the first round.
The problem was discovered in September last year just four days after the Czech's career-best performance reaching the semis of the Bitburger Open Grand Prix Gold.
"It was like my top result ever and I felt it was what I needed to get into the leading 20 or 30 in the world."
But after confiding in a doctor at party about something on his testicles he was sent to a specialist who insisted on an immediate operation.
"It was like crazy," Koukal recalled. "All your life changes in a second."
Four weeks after the operation, he underwent a tough three months of chemo, losing his hair in the process though it has since returned.
"But a light at the end of tunnel was the start of Olympic qualification," the Czech said. "It was good timing as I kept thinking about sport and badminton and it really helped me a lot."
An extra incentive was the Czech national championship in February which Koukal duly won - for a fifth time in succession.
"I practised for three weeks and it was really hard because recovery after training always took so long but I did it - a fifth title."
Since then he has been on the circuit with results "up and down" but this week's worlds have been an extra spur.
Unfortunately, there was a setback, the Czech losing 21-5 21-8 to Ukraine's Dmytro Zavadsky on Tuesday in a hugely disappointing result.
He said: "I had been practising hard and when I came on court I though this is going to be my day, I'm going to kick his ass and play another match tomorrow.
"Thirty minutes later I was off the court. It was such a nightmare. I've never had such a big loss. And the nightmare now is not knowing why."
After the early exit, Koukal plans a couple of weeks rest before starting training again for the next batch of Olympic qualifying tournaments in Europe.
Like Armstrong, the seven-time Tour de France champion, Koukal is involving himself back home with a special project to help spread the message about testicular cancer.
It includes making a documentary film which he hopes will air internationally after next year's Olympics.
The Czech also finds time to support the badminton charity Solibad, raising over 2,500 euros from auctions and exhibition matches recently to help children in Bali.
"I'm happy to be part of it and I hope to be able to help again," he said.