I think you need to convert it.  So something like this..

1. for (a=0; a < MyArrayList.size(); a++) {
   
2.       int[] stuffinarray = (int[]) MyArrayList.get(a);
3.       for (i=0; i < stuffinarray.length; i++) {
   
4.             println(stuffinarray[i]);
5.       }
6. }
   

It would have helped if you'd posted the code you're using to access the ArrayList arrays ;)
I suspect you're trying something like:

println(myArrayList);

To retrieve values from the arrays in the ArrayList you need to 'get' the arrays and then reference items in the arrays.  If you simply want to extract all values you can iterate through the ArrayList and then the internal arrays.  Like this:

1. String[] foo = {"a", "b", "c"};
2. String[] bar = {"d", "e", "f"};
3. ArrayList myContainer;
4. void setup() {
5.   myContainer = new ArrayList();
6.   myContainer.add(foo);
7.   myContainer.add(bar);
8.  
9.   for(int i=0; i<myContainer.size(); i++){
10.     String[] theCurrentArray = (String[]) myContainer.get(i);
11.     for(int j=0; j<theCurrentArray.length; j++) {
12.       println("myContainer: " + i + "  theCurrentArray: " + j + " = " + theCurrentArray[j]);
13.     }
14.   }
15.   println(myContainer);
16. }

Mind you - it might be worth you explaining where the data is coming from and what it is... You might be able to create a class specifically to store it that will make your life a lot easier in the long run ;)

Thanks a lot for quick helpful responses guys. Sorry for not posting code.

blindfish gave code for arrays of strings, you have to adapt the code (the type cast) to your arrays of integers.

Brilliant, thanks guys, works perfectly.