Pathological exam inations w hich included soil-block tests (test fungi: L entin ııs lep id eu s a n d G lo eo p lıyllu m tra b eu m ) w ere m ade on borings taken in 1976 from the upper surfaces o f 30 Iam inated crossties (upperm ost Iamination o f yeIlow birch, others o f jack pine) and from 9 Controls (single piece jack pine), ali treated vvith a creosote and petroleum -oil m ixture, and in service since 1948 in tw o areas in Canada (North Bay, O ntario, and St-L azare, Quebec). T he depth o f preservative penetration generally exceeded 30-50 m m , the length o f the borings. T he tw o narrovvest penetration zones (one 8, and the other 16 m m ) w ere m easured on borings from control ties. P reservative concen tration on borings from Iam inated ties w as visually assessed alvvays as “m edium ” or “high”, at least in the outer 12 m m portion. On the Controls, hovvever, preservative concentration w as assessed as “low ” in 7 out o f 18 borings, the rem ainder being “m edium ” or “high”. In tests vvith a m etal probe the borings from Iam inated ties w ere assessed in the yellow birch portions, and usually also in the jack pine portions, as “ norm al” ; tw enty percent o f the Controls, how ever, were assessed as “soft and w eakened” . In m icroscopic exam inations, none o f the borings w ere found to be attacked by B asidiom ycetes. Sporadic fungal hyphae w ere seen, but no evidence for fungal deterioration w as observed, except for one o f the control ties. Isolation attem pts yielded m oulds, vvood staining fungi, and once a C haetom ium sp. (from a control tie). N o B asidiom ycetes w ere isolated. i n th e soil-block tests th e b o rin g s from ties w ere gen erally m o re resistan t to d ecay th a n th o se fro m u n tre a te d w ood. A lthough in th e assesm ent th e borin g s fro m th e lam in ated ties seem ed to co n tain m ore p re serv a tiv e th an the co n tro l ties, in soil-block tests th ey show ed h ig h er resistan ce only to L. lepideus. In tests eig th G. trabeum th e opposite w as observ ed . O u te r p o rtio n s (5.5- 16.5 m m fro m th e su rface) o f th e lam in ated ties w ere highly re sista n t to fu n gal d ecay in tests b o th o f th e fungi used. F o r co n tro l ties th is w as tru e only in tests w ith G. trabeum . In th e ir resistan ce to fungal decay, b o rin g fro m th e la m in a te d ties in service in N o rth B ay an d in S t-L azare, (tw o locations of sim ila r c liın ate), w ere sim ila r to each other. As expected, L. lepideus, a creosote re sis ta n t fu n g u s, g en erally cau sed m o re decay on vvood fro m ties th a n G. trabeum . I t a p p e a rs th a t in th e p red ictio n o f th e re m a in in g service life o f th e ties e x a m in e d , fu n g a l d e ca y sh o u ld b e c o n sid ere d less im p o r ta n t th a n fa cto rs su ch as m ech an ical w e ar d u e to traffıc.