We establish some stability results over $p$--adic fields for the generalized quadratic functional equation $$\sum^{n}_{k=2}\sum^{k}_{i_{1}=2}\sum^{k+1}_{i_{2}=i_{1}+1}...\sum^{n}_{i_{n-k+1}=i_{n-k}+1} f\left(\sum^{n}_{i=1,i\neq i_{1},..,i_{n-k+1}}x_{i}-\sum^{n-k+1}_{r=1}x_{i_{r}}\right)+f\left(\sum^{n}_{i=1}x_{i}\right) =2^{n-1}\sum^{n}_{i=1}f\left(x_{i}\right)$$ where $n \in \mathbb{N}$ and $n \geq 2$.
