New values have been obtained for the magnetoelastic coefficients
h
3
and
h
4
of nickel at room temperature from ferromagnetic resonance experiments on (100) single crystal nickel films. The ratios of
h
3
/
h
1
and
h
4
/
h
1
are found to be 0.091 ± 0.007 and 0.153 ± 0.015 respectively which give
h
3
= (- 8.5 ± 0.7) x 10
-6
and
h
4
= (- 14.3 ± 1.4) x 10
-6
if the Lee & Asgar value of
h
3
is used (- 94 x 10
-6
). The magnetocrystalline anisotropy constant
K
1
, the saturation magnetization
M
and the spectroscopic splitting factor
g
have been measured also. It is found that
K
1
= ( - 5.4 ± 0.3) x 10
4
erg/cm
3
and that
g
= 2.161 ± 0.009 in agreement with published data on bulk samples but that the value of
M
is found to be higher than the bulk value by 1.6%. The discrepancies between the values of
h
3
,
h
4
and
M
as reported here and the bulk values are discussed. The theory of feromagnetic resonance has been extended to cover the five-constant representation of magnetostriction and to the
K
3
anisotropy term. The effect of the
g
factor having cubic anisotropy on the resonance conditions has been calculated.
