  In this work we present a multiwavelength study of narrow-line Seyfert 1
galaxies (NLS1s) discovered in the Second Byurakan Survey (SBS). The sample
consists of 26 objects, which have $M_{B}\ge -23.0$, or $-19.9 > M_{B} >
-23.0$, $0.0243 < z < 0.317$ and $15.2 < B < 19.0$. For these objects, we
present accurate coordinates, magnitudes, redshifts and the identification of
optical objects with X-ray, IR and radio sources. Several galaxies are
identified as X-ray or radio sources for the first time. We also report
spectroscopic and photometric data, the spectral energy distribution,
$\alpha_{ox}$ indices and other data. Our study shows that SBS NLS1s are strong
or moderately strong soft X-ray sources with $ \log L_{x}= 42.8-45.4$. Soft
X-ray luminous sources in our sample do not tend to be luminous in the
infrared. All SBS NLS1s are radio quiet objects ($ \log L_{R}<40.0$), and 52%
of them are strong FeII emitters (FeII$\lambda4570/H\beta >1$). The traditional
linear correlation $L_x$ and $L_{op}$, which seems to hold for AGN in general,
is found for SBS NLS1s. An anticorrelation between FWHM of ${H\beta}$ and the
ratio of FeII$\lambda4570/H\beta$ is also observed. A weak correlation is found
between $\alpha_{ox}$ slope and $L_{op}$. One of our main findings is that
almost all SBS NLS1s may not have a FIR bump. Their SED suggest that they may
also possess a BBB. The absence of IR bump in most of SBS NLS1s and the
weakness of X-ray radiation in some of them, may argue against the presence of
a BLR. The surface density of SBS NLS1s is $<$ 0.015 per $deg.^2$ ($B<17.5,
z<0.16$).
