D程式設計語言允許使用一個迴圈裡巢狀另一個迴圈。以下部分顯示幾個例子來說明這一概念。
語法巢狀在D環語句如下：
for ( init; condition; increment ) { for ( init; condition; increment ) { statement(s); } statement(s); }
在D程式設計語言while迴圈語句語法巢狀如下：
while(condition) { while(condition) { statement(s); } statement(s); }
巢狀do...while的語法在D程式設計語言回圈語句如下：
do { statement(s); do { statement(s); }while( condition ); }while( condition );
在迴圈巢狀最後需要說明的是，可以把任何型別的迴圈的任何其他型別的迴圈裡面。例如，一個for迴圈可以放在一個while迴圈中，反之亦然。
下面的程式使用一個巢狀的for迴圈來找出2-100的素數：
import std.stdio; int main () { /* local variable definition */ int i, j; for(i=2; i<100; i++) { for(j=2; j <= (i/j); j++) if(!(i%j)) break; // if factor found, not prime if(j > (i/j)) writefln("%d is prime", i); } return 0; }
當上面的程式碼被編譯並執行，它會產生以下結果：
2 is prime 3 is prime 5 is prime 7 is prime 11 is prime 13 is prime 17 is prime 19 is prime 23 is prime 29 is prime 31 is prime 37 is prime 41 is prime 43 is prime 47 is prime 53 is prime 59 is prime 61 is prime 67 is prime 71 is prime 73 is prime 79 is prime 83 is prime 89 is prime 97 is prime