We investigate the numbers of complex zeros of Littlewood polynomials
$p\left( z \right)$ (polynomials
with coefficients {−1, 1}) inside or on the unit circle
$\left| z \right|\,=\,1$, denoted by
$N\left( p \right)$ and
$U\left( p \right)$, respectively. Two types of Littlewood polynomials are considered: Littlewood polynomials with one sign change in
the sequence of coefficients and Littlewood polynomials with one negative coefficient. We obtain
explicit formulas for
$N\left( p \right)$,
$U\left( p \right)$ for polynomials
$p\left( z \right)$ of these types. We show that if
$n\,+\,1$ is a prime number, then for each integer
$k,\,0\,⩽\,k\,⩽\,n-1$, there exists a Littlewood polynomial
$p\left( z \right)$ of degree
$n$ with
$N\left( p \right)\,=\,k$ and
$U\left( p \right)\,=\,0$. Furthermore, we describe some cases where the ratios
$N\left( p \right)/n$ and
$U\left( p \right)/n$ have limits as
$n\,\to \,\infty $ and find the corresponding limit values.