Brown the chicken in the pan where you will cook the risotto.
This will give your risotto some nice flavor if you make sure to scoop up the browned bits during cooking.
Then remove it.
Let it rest on a plate, tented with foil,
throughout the whole time you are making the risotto.
Towards the last few minutes, put the chicken and any accumulated drippings from the plate back in.
This will warm the chicken and add the flavor from the drippings.
I use this technique whenever I am doing any sort of single skillet dish with meat, starch, and veggies.
cooking.stackexchange.com/users/1816/justkt
Cook the chicken separately, and add it to the risotto towards the end.
Whenever I make risotto, I usually cook everything but the rice and some aromatic vegetables separately and add it towards the end of cooking.
cooking.stackexchange.com/users/3342/Magnus Nordlander
just an opinion.. Wouldn't cooking the chicken together with the risotto add extra favour to the risotto?
Also, which part of chicken did you use?
Have you tried to use chicken thigh which is harder to get dried out?
cooking.stackexchange.com/users/2951/Foodrules 
Brown the chicken in the risotto pan on both sides.
Put in an ovenproof dish/casserole and add chicken stock approximately 1/2" (1cm) up the side of the dish.
Roast for around 20-25 minutes @ 395F (200C).
When done, pour the remaining stock into the risotto stock for extra chickeny flavour.
Slice/chop the chicken and add to the risotto just before serving (though this depends on how long you've left the chicken sitting).
Roasting the chicken beforehand removes any worries about the chicken not being cooked, providing of course you cook it through (and believe me, undercooked chicken is not good ).
Adding the stock to the dish helps keep the meat moist and imbues it with extra flavour (breast meat especially is often quite bland).
cooking.stackexchange.com/users/4194/ElendilTheTall
Restaurants often cook this way.
Cook ingredients separately, to carefully control each cooking time/ process.
If you want to meld flavones use chicken stock for the risotto, or a vegetable stock for deglazing chicken.
Add it all together at the end.
cooking.stackexchange.com/users/4179/Chef
I was following a recipe for a chicken risotto, which said to brown the chicken (breast meat, cut into small pieces, maybe 3/4 of an inch or so) in the pan after browning the onions, and then add the rice and stock to the same pan afterwards (so the chicken was in the pan the entire cooking period of the rice). However, when the dish was complete, many of the chicken pieces had unfortunately dried out.  What can I do to prevent this next time?
Cooking chicken in a risotto without it drying out
cooking.stackexchange.com
<chicken><italian-cuisine><risotto>
cooking.stackexchange.com/questions/10742
cooking.stackexchange.com/users/950/Daniel Vandersluis
Cook the ingredients separately and add them towards the end of the cooking process to control the cooking time. Cook the chicken separately and add in at the end.
It is common to cook the chicken separately and add it in at the end.