This paper is concerned with the regularity criteria in terms of the middle eigenvalue of the deformation (strain) tensor $$\mathcal {D}(u)$$
D
(
u
)
to the 3D Navier–Stokes equations in Lorentz spaces. It is shown that a Leray–Hopf weak solution is regular on (0, T] provided that the norm $$\Vert \lambda _{2}^{+}\Vert _{L^{p,\infty }(0,T; L ^{q,\infty }(\mathbb {R}^{3}))} $$
‖
λ
2
+
‖
L
p
,
∞
(
0
,
T
;
L
q
,
∞
(
R
3
)
)
with $$ {2}/{p}+{3}/{q}=2$$
2
/
p
+
3
/
q
=
2
$$( {3}/{2}<q\le \infty )$$
(
3
/
2
<
q
≤
∞
)
is small. This generalizes the corresponding works of Neustupa–Penel and Miller.